Commit Graph

820 Commits

Author SHA1 Message Date
Will Deacon da48d094ce Kconfig: remove HAVE_LATENCYTOP_SUPPORT
As illustrated by commit a3afe70b83 ("[S390] latencytop s390
support."), HAVE_LATENCYTOP_SUPPORT is defined by an architecture to
advertise an implementation of save_stack_trace_tsk.

However, as of 9212ddb5ea ("stacktrace: provide save_stack_trace_tsk()
weak alias") a dummy implementation is provided if STACKTRACE=y.  Given
that LATENCYTOP already depends on STACKTRACE_SUPPORT and selects
STACKTRACE, we can remove HAVE_LATENCYTOP_SUPPORT altogether.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Helge Deller <deller@gmx.de>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-16 11:17:23 -08:00
Kirill A. Shutemov e1534ae950 mm: differentiate page_mapped() from page_mapcount() for compound pages
Let's define page_mapped() to be true for compound pages if any
sub-pages of the compound page is mapped (with PMD or PTE).

On other hand page_mapcount() return mapcount for this particular small
page.

This will make cases like page_get_anon_vma() behave correctly once we
allow huge pages to be mapped with PTE.

Most users outside core-mm should use page_mapcount() instead of
page_mapped().

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Tested-by: Sasha Levin <sasha.levin@oracle.com>
Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: Jerome Marchand <jmarchan@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Steve Capper <steve.capper@linaro.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-15 17:56:32 -08:00
Linus Torvalds 0f0836b7eb Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching
Pull livepatching updates from Jiri Kosina:

 - RO/NX attribute fixes for patch module relocations from Josh
   Poimboeuf.  As part of this effort, module.c has been cleaned up as
   well and livepatching is piggy-backing on this cleanup.  Rusty is OK
   with this whole lot going through livepatching tree.

 - symbol disambiguation support from Chris J Arges.  That series is
   also

        Reviewed-by: Miroslav Benes <mbenes@suse.cz>

   but this came in only after I've alredy pushed out.  Didn't want to
   rebase because of that, hence I am mentioning it here.

 - symbol lookup fix from Miroslav Benes

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching:
  livepatch: Cleanup module page permission changes
  module: keep percpu symbols in module's symtab
  module: clean up RO/NX handling.
  module: use a structure to encapsulate layout.
  gcov: use within_module() helper.
  module: Use the same logic for setting and unsetting RO/NX
  livepatch: function,sympos scheme in livepatch sysfs directory
  livepatch: add sympos as disambiguator field to klp_reloc
  livepatch: add old_sympos as disambiguator field to klp_func
2016-01-14 16:38:02 -08:00
Vineet Gupta 6b538db7c6 ARC: dw2 unwind: Catch Dwarf SNAFUs early
Instead of seeing empty stack traces, let kernel fail early so dwarf
issues can be fixed sooner

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-12-21 14:01:49 +05:30
Vineet Gupta 6d0d506012 ARC: dw2 unwind: Don't bail for CIE.version != 1
The rudimentary CIE.version == 3 handling is already present in code
(for return address register specification)

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-12-21 14:01:25 +05:30
Vineet Gupta 2d64affc92 Revert "ARC: dw2 unwind: Ignore CIE version !=1 gracefully instead of bailing"
Blingly ignoring CIE.version != 1 was a bad idea.
It still leaves "desirability" when running perf with callgraphing where libgcc
symbols might show in hotspot.

More importantly, basic CIE.version == 3 support already exists in code:

|
|   retAddrReg = state.version <= 1 ? *ptr++ : get_uleb128(&ptr, end);
|

Next commit with simply add continue-not-bail for CIE.version != 1

This reverts commit 323f41f9e7.
2015-12-21 13:29:44 +05:30
Vineet Gupta 07fd7d4bbc ARC: Fix linking errors with CONFIG_MODULE + CONFIG_CC_OPTIMIZE_FOR_SIZE
At -Os, ARC gcc generates millicode thunk for function prologue/epilogue,
which are served by libgcc.

Modules historically are NOT linked with libgcc to avoid code bloat, reducing
runtime relocation fixups etc. I even once tried doing that but got lost
in makefile intricacies.

This means modules at -Os don't get the millicode thunks, causing build
failures below:

| MODPOST 5 modules
| ERROR: "__ld_r13_to_r18" [crypto/sha256_generic.ko] undefined!
| ERROR: "__ld_r13_to_r18_ret" [crypto/sha256_generic.ko] undefined!
| ERROR: "__st_r13_to_r18" [crypto/sha256_generic.ko] undefined!
| ERROR: "__ld_r13_to_r17_ret" [crypto/sha256_generic.ko] undefined!
| ERROR: "__st_r13_to_r17" [crypto/sha256_generic.ko] undefined!
| ERROR: "__ld_r13_to_r16_ret" [crypto/sha256_generic.ko] undefined!
| ERROR: "__st_r13_to_r16" [crypto/sha256_generic.ko] undefined!
|....
|....

Workaround that by inhibiting millicode thunks for loadable modules

Fixes STAR 9000641864:
("Linux built with optimizations for size emits errors for modules")

Reported-by: Anton Kolesov <akolesov@synosys.com>
Cc: Michal Marek <mmarek@suse.cz>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-12-21 13:01:19 +05:30
Alexey Brodkin 4b32e89af7 ARC: mm: fix building for MMU v2
ARC700 cores with MMU v2 don't have IC_PTAG AUX register and so we only
define ARC_REG_IC_PTAG for MMU versions >= 3.

But current implementation of cache_line_loop_vX() routines assumes
availability of all of them (v2, v3 and v4) simultaneously.

And given undefined ARC_REG_IC_PTAG if CONFIG_MMU_VER=2 we're seeing
compilation problem:
---------------------------------->8-------------------------------
  CC      arch/arc/mm/cache.o
arch/arc/mm/cache.c: In function '__cache_line_loop_v3':
arch/arc/mm/cache.c:270:13: error: 'ARC_REG_IC_PTAG' undeclared (first use in this function)
   aux_tag = ARC_REG_IC_PTAG;
             ^
arch/arc/mm/cache.c:270:13: note: each undeclared identifier is reported only once for each function it appears in
scripts/Makefile.build:258: recipe for target 'arch/arc/mm/cache.o' failed
---------------------------------->8-------------------------------

The simples fix is to have ARC_REG_IC_PTAG defined regardless MMU
version being used.

We don't use it in cache_line_loop_v2() anyways so who cares.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-12-21 12:10:40 +05:30
Vineet Gupta 899cfd2bb0 ARC: mm: HIGHMEM: Fix section mismatch splat
| WARNING: vmlinux.o(.text+0xd6c2): Section mismatch in reference from the function alloc_kmap_pgtable() to the function
| .init.text:__alloc_bootmem_low()
The function alloc_kmap_pgtable() references the function __init __alloc_bootmem_low().
This is often because alloc_kmap_pgtable lacks a __init annotation or the annotation of __alloc_bootmem_low is wrong.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-12-21 12:10:40 +05:30
Vineet Gupta 575a9d4e2c ARC: smp: Rename platform hook @init_cpu_smp -> @init_per_cpu
Makes it similar to smp_ops which also has callback with same name

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-12-17 12:56:56 +05:30
Noam Camus b474a02382 ARC: rename smp operation init_irq_cpu() to init_per_cpu()
This will better reflect its description i.e. "any needed setup..."
and not just do an "IPI request".

Signed-off-by: Noam Camus <noamc@ezchip.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-12-17 12:56:43 +05:30
Vineet Gupta 323f41f9e7 ARC: dw2 unwind: Ignore CIE version !=1 gracefully instead of bailing
ARC dwarf unwinder only supports CIE version == 1
The boot time dwarf sanitizer (part of binary lookup table constructor)
would simply bail if it saw CIE version == 3, rendering unwinder with a
NULL lookup table.

It seems libgcc linked with kernel does have such entries.

With fallback linear search removed, and a NULL binary lookup table,
unwinder fails to generate any stack trace.

So allow graceful ignoring of unsupported CIE entries.

This problem was initially seen in Alexey's setup (and not mine) as he
was using buildroot built toolchain (libgcc) which doesn't get built with
CFLAGS_FOR_TARGET="-gdwarf-2 which is my default

Fixes STAR 9000985048: "kernel unwinder broken with stock tools"

Fixes: 2e22502c08 ARC: dw2 unwind: Remove falllback linear search thru FDE entries
Reported-by Alexey Brodkin <abrodkin@synopsys.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-12-17 11:10:23 +05:30
Vineet Gupta bc79c9a721 ARC: dw2 unwind: Reinstante unwinding out of modules
The fix which removed linear searching of dwarf (because binary lookup
data always exists) missed out on the fact that modules don't get the
binary lookup tables info. This caused unwinding out of modules to stop
working.

So add binary lookup header setup (equivalent of eh_frame_hdr setup) to
modules as well.

While at it, confine the header setup to within unwinder code,
reducing one API exposed out of unwinder code.

Fixes: 2e22502c08 ARC: dw2 unwind: Remove falllback linear search thru FDE entries
Cc: <stable@vger.kernel.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-12-17 11:10:23 +05:30
Vineet Gupta ff1c0b6a79 ARC: [plat-sim] unbork non default CONFIG_LINUX_LINK_BASE
HIGHMEM support bumped the default memory size for nsim platform to 1G.
Thus total memory ended at the very edge of start of peripherals address
space. With linux link base shifted, memory started bleeding into
peripheral space which caused early boot bad_page spew !

Fixes: 29e332261d ("ARC: mm: HIGHMEM: populate high memory from DT")
Reported-by: Anton Kolesov <akolesov@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-12-17 11:06:43 +05:30
Vineet Gupta c512c6ba7a ARC: intc: Document arc_request_percpu_irq() better
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-12-12 16:04:12 +05:30
Vineet Gupta c6317bc7c5 ARCv2: perf: Ensure perf intr gets enabled on all cores
This was the second perf intr issue

perf sampling on multicore requires intr to be enabled on all cores.
ARC perf probe code used helper arc_request_percpu_irq() which calls
 - request_percpu_irq() on core0
 - enable_percpu_irq() on all all cores (including core0)

genirq requires that request be made ahead of enable call.
However if perf probe happened on non core0 (observed on a 3.18 kernel),
enable would get called ahead of request, failing obviously and
rendering perf intr disabled on all such cores

[   11.120000] 1 ARC perf       : 8 counters (48 bits), 113 conditions, [overflow IRQ support]
[   11.130000] 1 -----> enable_percpu_irq() IRQ 20 failed
[   11.140000] 3 -----> enable_percpu_irq() IRQ 20 failed
[   11.140000] 2 -----> enable_percpu_irq() IRQ 20 failed
[   11.140000] 0 =====> request_percpu_irq() IRQ 20
[   11.140000] 0 -----> enable_percpu_irq() IRQ 20

Fix this fragility, by calling request_percpu_irq() on whatever core
calls probe (there is no requirement on which core calls this anyways)
and then calling enable on each cores.

Interestingly this started as invesigation of STAR 9000838902:
"sporadically IRQs enabled on perf prob"

which was about occassional boot spew as request_percpu_irq got called
non-locally (from an IPI), and re-enabled interrupts in following path
proc_mkdir ->  spin_unlock_irq()

which the irq work code didn't like.

| ARC perf     : 8 counters (48 bits), 113 conditions, [overflow IRQ support]
|
| BUG: failure at ../kernel/irq_work.c:135/irq_work_run_list()!
| CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.18.10-01127-g285efb8e66d1 #2
|
| Stack Trace:
|  arc_unwind_core.constprop.1+0x94/0x104
|  dump_stack+0x62/0x98
|  irq_work_run_list+0xb0/0xb4
|  irq_work_run+0x22/0x3c
|  do_IPI+0x74/0x9c
|  handle_irq_event_percpu+0x34/0x164
|  handle_percpu_irq+0x58/0x78
|  generic_handle_irq+0x1e/0x2c
|  arch_do_IRQ+0x3c/0x60
|  ret_from_exception+0x0/0x8

Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-snps-arc@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Cc: Alexey Brodkin <abrodkin@synopsys.com>
Cc: <stable@vger.kernel.org> #4.2+
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-12-12 16:03:59 +05:30
Vineet Gupta 5bf704c204 ARC: intc: No need to clear IRQ_NOAUTOEN
arc_request_percpu_irq() is called by all cores to request/enable percpu
irq. It has some "prep" calls needed by genirq:
 - setup percpu devid
 - disable IRQ_NOAUTOEN

However given that enable_percpu_irq() is called enayways, latter can be
avoided.

We are now left with irq_set_percpu_devid() quirk and that too for
ARCompact builds only, since previous patch updated ARCv2 intc to do this
in the "right" place, i.e. irq map function.

By next release, this will ultimately be fixed for ARCompact as well.

Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Alexey Brodkin <abrodkin@synopsys.com>
Cc: linux-snps-arc@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-12-12 16:03:59 +05:30
Vineet Gupta 8eb0984bf4 ARCv2: intc: Fix random perf irq disabling in SMP setup
As part of fixing another perf issue, observed that after a perf run,
the interrupt got disabled on one/more cores.

Turns out that despite requesting perf irq as percpu, the flow handler
registered was not handle_percpu_irq()

Given that on ARCv2 cores, IRQs < 24 are always private to cpu, we
register the right handler at the very onset.

Before Fix

| [ARCLinux]# cat /proc/interrupts | grep perf
|  20:    0      0      0       0  ARCv2 core Intc  20 ARC perf counters
|
| [ARCLinux]# perf record -c 20000 /sbin/hackbench
| Running with 10*40 (== 400) tasks.
|
| [ARCLinux]# cat /proc/interrupts | grep perf
|  20:    0    522      8    51916  ARCv2 core Intc  20 ARC perf counters
|
| [ARCLinux]# perf record -c 20000 /sbin/hackbench
| Running with 10*40 (== 400) tasks.
|
| [ARCLinux]# cat /proc/interrupts | grep perf
|  20:    0    522      8   104368  ARCv2 core Intc  20 ARC perf counters

After Fix

| [ARCLinux]# cat /proc/interrupts | grep perf
|  20:    0      0      0       0  ARCv2 core Intc  20 ARC perf counters
|
| [ARCLinux]# perf record -c 20000 /sbin/hackbench
| Running with 10*40 (== 400) tasks.
|
| [ARCLinux]# cat /proc/interrupts | grep perf
|  20:  64198  62012  62697  67803  ARCv2 core Intc  20 ARC perf counters
|
| [ARCLinux]# perf record -c 20000 /sbin/hackbench
| Running with 10*40 (== 400) tasks.
|
| [ARCLinux]# cat /proc/interrupts | grep perf
|  20: 126014 122792 123301 133654  ARCv2 core Intc  20 ARC perf counters

Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Alexey Brodkin <abrodkin@synopsys.com>
Cc: stable@vger.kernel.org #4.2+
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-12-12 16:03:41 +05:30
Alexey Brodkin 6d1a2adef7 ARC: [axs10x] cap ethernet phy to 100 Mbit/sec
Current ARC SDP boards cannot reliably handle 1Gbit
Ethernet connections due to limitations in hardware.

To make sure networking is stable on the board we're
limiting phy to 100 Mbit.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-12-07 19:40:03 +05:30
Rusty Russell 7523e4dc50 module: use a structure to encapsulate layout.
Makes it easier to handle init vs core cleanly, though the change is
fairly invasive across random architectures.

It simplifies the rbtree code immediately, however, while keeping the
core data together in the same cachline (now iff the rbtree code is
enabled).

Acked-by: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2015-12-04 22:46:25 +01:00
Vineet Gupta 2e22502c08 ARC: dw2 unwind: Remove falllback linear search thru FDE entries
Fixes STAR 9000953410: "perf callgraph profiling causing RCU stalls"

| perf record -g -c 15000 -e cycles /sbin/hackbench
|
| INFO: rcu_preempt self-detected stall on CPU
| 1: (1 GPs behind) idle=609/140000000000002/0 softirq=2914/2915 fqs=603
| Task dump for CPU 1:

in-kernel dwarf unwinder has a fast binary lookup and a fallback linear
search (which iterates thru each of ~11K entries) thus takes 2 orders of
magnitude longer (~3 million cycles vs. 2000). Routines written in hand
assembler lack dwarf info (as we don't support assembler CFI pseudo-ops
yet) fail the unwinder binary lookup, hit linear search, failing
nevertheless in the end.

However the linear search is pointless as binary lookup tables are created
from it in first place. It is impossible to have binary lookup fail while
succeed the linear search. It is pure waste of cycles thus removed by
this patch.

This manifested as RCU stalls / NMI watchdog splat when running
hackbench under perf with callgraph profiling. The triggering condition
was perf counter overflowing in routine lacking dwarf info (like memset)
leading to patheic 3 million cycle unwinder slow path and by the time it
returned new interrupts were already pending (Timer, IPI) and taken
rightaway. The original memset didn't make forward progress, system kept
accruing more interrupts and more unwinder delayes in a vicious feedback
loop, ultimately triggering the NMI diagnostic.

Cc: stable@vger.kernel.org
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-11-23 21:36:49 +05:30
Vineet Gupta e81b75f7b2 ARC: remove SYNC from __switch_to()
SYNC in __switch_to() is a historic relic and not needed at all.

 - In UP context it is obviously useless, why would we want to stall
   the core for all updates to stack memory of t0 to complete before
   loading kernel mode callee registers from t1 stack's memory.

 - In SMP, there could be potential race in which outgoing task could
   be concurrently picked for running on a different core, thus writes
   to stack here need to be visible before the reads from stack on
   other core. Peter confirmed that generic schedular already has needed
   barriers (by way of rq lock) so there is no need for additional arch
   barrier.

This came up when Noam was trying to replace this SYNC with EZChip
specific hardware thread scheduling instruction for their platform
support.

Link: http://lkml.kernel.org/r/20151102092654.GM17308@twins.programming.kicks-ass.net
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org
Cc: Noam Camus <noamc@ezchip.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-11-17 22:05:30 +05:30
Vineet Gupta b8628f3fe4 ARCv2: Use the default irq priority for idle sleep
Although kernel doesn't support the multiple IRQ priority levels provided
by HS38x core intc yet, ensure that the default prio value is used
anyways by relevant code.

SLEEP insn needs to be provided the IRQ priority level which can
interrupt it. This needs to be the default level which maynot
necessarily be 0 as assumed by current code.

This change allows a kernel with ARCV2_IRQ_DEF_PRIO = 1 to boot fine.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-11-16 14:17:06 +05:30
Vineet Gupta 512b5b89b9 ARC: Abstract out ISA specific SLEEP args
No semantical changes, prepares for ARCv2 specific change in next commit

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-11-16 14:17:02 +05:30
Vineet Gupta 61a1634818 ARC: comments update
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-11-16 12:00:16 +05:30
sujayraaj 17c4fbaf1a ARC: switch to arc-linux- CROSS_COMPILE prefix across all configs
When building kernel with buildroot built toolchain, CROSS_COMPILE
currently needs adjustment even if minor. This is because the defconfigs
prefer "arc-linux-uclibc-" prefix from hand built (non buildroot) toolchain
while buildroot provides "arc-buildroot-linux-uclibc-"

To avoid this use the common "arc-linux-" prefix which is provided by
buildroot and has also been in hand built tools for quite some time.

Signed-off-by: sujayraaj <sujayraaj@gmail.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
[vgupta: updated changelog]
2015-11-16 12:00:09 +05:30
Linus Torvalds b3a0d9a232 ARC fixes for 4.4-rc1
- A bunch of brown paper bag bugs (MAINTAINERS list email, SMP build failure)
 - cpu_relax() now compiler barrier for UP as well
 - Handling of userspace Bus Errors for ARCompact builds
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Merge tag 'arc-4.4-rc1-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc

Pull ARC fixes from Vineet Gupta:
 "Found a couple of brown paper bag bugs with the prev pull request
  (including a SMP build breakage report from Guenter).  Since these are
  urgent I also decided to send over a bunch of other pending fixes
  which could have otherwise waited an rc or two.

  Summary:

   - A bunch of brown paper bag bugs (MAINTAINERS list email, SMP build
     failure)
   - cpu_relax() now compiler barrier for UP as well
   - handling of userspace Bus Errors for ARCompact builds"

* tag 'arc-4.4-rc1-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
  ARC: Fix silly typo in MAINTAINERS file
  ARC: cpu_relax() to be compiler barrier even for UP
  ARC: use ASL assembler mnemonic
  ARC: [arcompact] Handle bus error from userspace as Interrupt not exception
  ARC: remove extraneous header include
  ARCv2: lib: memcpy: use local symbols
2015-11-14 09:09:37 -08:00
Vineet Gupta 1cfc05cbe2 ARC: cpu_relax() to be compiler barrier even for UP
cpu_relax() on ARC has been barrier only for SMP (and no-op for UP). Per
recent discussions, it is safer to make it a compiler barrier
unconditionally.

Link: http://lkml.kernel.org/r/53A7D3AA.9020100@synopsys.com
Acked-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-11-14 13:12:30 +05:30
Vineet Gupta a6416f57ce ARC: use ASL assembler mnemonic
ARCompact and ARCv2 only have ASL, while binutils used to support LSL as
a alias mnemonic.

Newer binutils (upstream) don't want to do that so replace it.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-11-14 13:12:21 +05:30
Vineet Gupta 541366da6a ARC: [arcompact] Handle bus error from userspace as Interrupt not exception
Bus errors from userspace on ARCompact based cores are handled by core
as a high priority L2 interrupt but current code treated it as interrupt
Handling an interrupt like exception is certainly not going to go unnoticed.
(and it worked so far as we never saw a Bus error from userspace until
IPPK guys tested a DDR controller with ECC error detection etc hence
needed to explicitly trigger/handle such errors)

 - So move mem_service exception handler from common code into ARCv2 code.
 - In ARCompact code, define  mem_service as L2 interrupt handler which
   just drops down to pure kernel mode and goes of to enqueue SIGBUS

Reported-by: Nelson Pereira <npereira@synopsys.com>
Tested-by: Ana Martins <amartins@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-11-14 13:12:20 +05:30
Vineet Gupta 76a8c40c65 ARC: remove extraneous header include
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-11-14 13:11:38 +05:30
Linus Torvalds 9bbd4b9f38 DeviceTree updates for 4.4:
- DT binding doc consolidation moving similar bindings to common
   locations. The majority of these are display related which were
   scattered in video/, fb/, drm/, gpu/, and panel/ directories.
 - Add new config option, CONFIG_OF_ALL_DTBS, to enable building all dtbs
   in the tree for most arches with dts files (except powerpc for now).
 - OF_IRQ=n fixes for user enabled CONFIG_OF.
 - of_node_put ref counting fixes from Julia Lawall.
 - Common DT binding for wakeup-source and deprecation of all similar
   bindings.
 - DT binding for PXA LCD controller.
 - Allow ignoring failed PCI resource translations in order to ignore
   64-bit addresses on non-LPAE 32-bit kernels.
 - Support setting the NUMA node from DT instead of only from parent
   device.
 - Couple of earlycon DT parsing fixes for address and options.
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Merge tag 'devicetree-for-4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux

Pull DeviceTree updates from Rob Herring:
 "A fairly large (by DT standards) pull request this time with the
  majority being some overdue moving DT binding docs around to
  consolidate similar bindings.

   - DT binding doc consolidation moving similar bindings to common
     locations.  The majority of these are display related which were
     scattered in video/, fb/, drm/, gpu/, and panel/ directories.

   - Add new config option, CONFIG_OF_ALL_DTBS, to enable building all
     dtbs in the tree for most arches with dts files (except powerpc for
     now).

   - OF_IRQ=n fixes for user enabled CONFIG_OF.

   - of_node_put ref counting fixes from Julia Lawall.

   - Common DT binding for wakeup-source and deprecation of all similar
     bindings.

   - DT binding for PXA LCD controller.

   - Allow ignoring failed PCI resource translations in order to ignore
     64-bit addresses on non-LPAE 32-bit kernels.

   - Support setting the NUMA node from DT instead of only from parent
     device.

   - Couple of earlycon DT parsing fixes for address and options"

* tag 'devicetree-for-4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux: (45 commits)
  MAINTAINERS: update DT binding doc locations
  devicetree: add Sigma Designs vendor prefix
  of: simplify arch_find_n_match_cpu_physical_id() function
  Documentation: arm: Fixed typo in socfpga fpga mgr example
  Documentation: devicetree: fix reference to legacy wakeup properties
  Documentation: devicetree: standardize/consolidate on "wakeup-source" property
  drivers: of: removing assignment of 0 to static variable
  xtensa: enable building of all dtbs
  mips: enable building of all dtbs
  metag: enable building of all dtbs
  metag: use common make variables for dtb builds
  h8300: enable building of all dtbs
  arm64: enable building of all dtbs
  arm: enable building of all dtbs
  arc: enable building of all dtbs
  arc: use common make variables for dtb builds
  of: add config option to enable building of all dtbs
  of/fdt: fix error checking for earlycon address
  of/overlay: add missing of_node_put
  of/platform: add missing of_node_put
  ...
2015-11-06 12:17:09 -08:00
Linus Torvalds d63a978865 Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking changes from Ingo Molnar:
 "The main changes in this cycle were:

   - More gradual enhancements to atomic ops: new atomic*_read_ctrl()
     ops, synchronize atomic_{read,set}() ordering requirements between
     architectures, add atomic_long_t bitops.  (Peter Zijlstra)

   - Add _{relaxed|acquire|release}() variants for inc/dec atomics and
     use them in various locking primitives: mutex, rtmutex, mcs, rwsem.
     This enables weakly ordered architectures (such as arm64) to make
     use of more locking related optimizations.  (Davidlohr Bueso)

   - Implement atomic[64]_{inc,dec}_relaxed() on ARM.  (Will Deacon)

   - Futex kernel data cache footprint micro-optimization.  (Rasmus
     Villemoes)

   - pvqspinlock runtime overhead micro-optimization.  (Waiman Long)

   - misc smaller fixlets"

* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  ARM, locking/atomics: Implement _relaxed variants of atomic[64]_{inc,dec}
  locking/rwsem: Use acquire/release semantics
  locking/mcs: Use acquire/release semantics
  locking/rtmutex: Use acquire/release semantics
  locking/mutex: Use acquire/release semantics
  locking/asm-generic: Add _{relaxed|acquire|release}() variants for inc/dec atomics
  atomic: Implement atomic_read_ctrl()
  atomic, arch: Audit atomic_{read,set}()
  atomic: Add atomic_long_t bitops
  futex: Force hot variables into a single cache line
  locking/pvqspinlock: Kick the PV CPU unconditionally when _Q_SLOW_VAL
  locking/osq: Relax atomic semantics
  locking/qrwlock: Rename ->lock to ->wait_lock
  locking/Documentation/lockstat: Fix typo - lokcing -> locking
  locking/atomics, cmpxchg: Privatize the inclusion of asm/cmpxchg.h
2015-11-03 16:10:43 -08:00
Linus Torvalds 2c2b8285dc - Support for new MM features in ARCv2 cores (THP, PAE40)
Some generic THP bits are touched - all ACKed by Kirill
 
 - Platform framework updates to prepare for EZChip arrival (still in works)
 
 - ARC Public Mailing list setup finally (linux-snps-arc@lists.infraded.org)
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Merge tag 'arc-4.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc

Pull ARC updates from Vineet Gupta:

 - Support for new MM features in ARCv2 cores (THP, PAE40) Some generic
   THP bits are touched - all ACKed by Kirill

 - Platform framework updates to prepare for EZChip arrival (still in works)

 - ARC Public Mailing list setup finally (linux-snps-arc@lists.infraded.org)

* tag 'arc-4.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc: (42 commits)
  ARC: mm: PAE40 support
  ARC: mm: PAE40: tlbex.S: Explicitify the size of pte_t
  ARC: mm: PAE40: switch to using phys_addr_t for physical addresses
  ARC: mm: HIGHMEM: populate high memory from DT
  ARC: mm: HIGHMEM: kmap API implementation
  ARC: mm: preps ahead of HIGHMEM support #2
  ARC: mm: preps ahead of HIGHMEM support
  ARC: mm: use generic macros _BITUL()/_AC()
  ARC: mm: Improve Duplicate PD Fault handler
  MAINTAINERS: Add public mailing list for ARC
  ARC: Ensure DT mem base is same as what kernel is built with
  ARC: boot: Non Master cpus only need to call EARLY_CPU_SETUP once
  ARCv2: smp: [plat-*]: No need to explicitly call mcip_init_smp()
  ARC: smp: Introduce smp hook @init_irq_cpu called for all cores
  ARC: smp: Rename platform hook @init_smp -> @init_cpu_smp
  ARCv2: smp: [plat-*]: No need to explicitly call mcip_init_early_smp()
  ARC: smp: Introduce smp hook @init_early_smp for Master core
  ARC: remove @init_time, @init_irq platform callbacks
  ARC: smp: irqchip: handle IPI as percpu irq like timer
  ARC: boot: Support Halt-on-reset and Run-on-reset SMP booting modes
  ...
2015-11-03 13:21:09 -08:00
Vineet Gupta ac506b7f22 ARCv2: lib: memcpy: use local symbols
Otherwise perf profiles don't charge tme to memcpy

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-11-03 17:33:00 +05:30
Vineet Gupta 5a364c2a17 ARC: mm: PAE40 support
This is the first working implementation of 40-bit physical address
extension on ARCv2.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-29 18:41:30 +05:30
Vineet Gupta 25d464183c ARC: mm: PAE40: tlbex.S: Explicitify the size of pte_t
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-28 19:50:29 +05:30
Vineet Gupta 28b4af729f ARC: mm: PAE40: switch to using phys_addr_t for physical addresses
That way a single flip of phys_addr_t to 64 bit ensures all places
dealing with physical addresses get correct data

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-28 19:50:29 +05:30
Vineet Gupta 29e332261d ARC: mm: HIGHMEM: populate high memory from DT
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-28 19:50:26 +05:30
Vineet Gupta 45890f6d34 ARC: mm: HIGHMEM: kmap API implementation
Implement kmap* API for ARC.

This enables
 - permanent kernel maps (pkmaps): :kmap() API
 - fixmap : kmap_atomic()

We use a very simple/uniform approach for both (unlike some of the other
arches). So fixmap doesn't use the customary compile time address stuff.
The important semantic is sleep'ability (pkmap) vs. not (fixmap) which
the API guarantees.

Note that this patch only enables highmem for subsequent PAE40 support
as there is no real highmem for ARC in pure 32-bit paradigm as explained
below.

ARC has 2:2 address split of the 32-bit address space with lower half
being translated (virtual) while upper half unstranslated
(0x8000_0000 to 0xFFFF_FFFF). kernel itself is linked at base of
unstranslated space (i.e. 0x8000_0000 onwards), which is mapped to say
DDR 0x0 by external Bus Glue logic (outside the core). So kernel can
potentially access 1.75G worth of memory directly w/o need for highmem.
(the top 256M is taken by uncached peripheral space from 0xF000_0000 to
0xFFFF_FFFF)

In PAE40, hardware can address memory beyond 4G (0x1_0000_0000) while
the logical/virtual addresses remain 32-bits. Thus highmem is required
for kernel proper to be able to access these pages for it's own purposes
(user space is agnostic to this anyways).

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-28 19:49:04 +05:30
Vineet Gupta 6101be5ad4 ARC: mm: preps ahead of HIGHMEM support #2
Explicit'ify that all memory added so far is low memory
Nothing semantical

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-28 19:49:00 +05:30
Vineet Gupta 336e2136e1 ARC: mm: preps ahead of HIGHMEM support
Before we plug in highmem support, some of code needs to be ready for it
 - copy_user_highpage() needs to be using the kmap_atomic API
 - mk_pte() can't assume page_address()
 - do_page_fault() can't assume VMALLOC_END is end of kernel vaddr space

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-28 19:31:05 +05:30
Alexey Brodkin d40846457f ARC: mm: use generic macros _BITUL()/_AC()
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-28 19:31:05 +05:30
Vineet Gupta 8840e14cd8 ARC: mm: Improve Duplicate PD Fault handler
- Move the verbosity knob from .data to .bss by using inverted logic
 - No need to readout PD1 descriptor
 - clip the non pfn bits of PD0 to avoid clipping inside the loop

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-28 19:31:04 +05:30
Vineet Gupta f759ee57b2 ARC: Ensure DT mem base is same as what kernel is built with
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-28 16:13:42 +05:30
Vineet Gupta 483bcc99c0 ARC: boot: Non Master cpus only need to call EARLY_CPU_SETUP once
With prev fixes, all cores now start via common entry point @stext which
already calls EARLY_CPU_SETUP for all cores - so no need to invoke it
again

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-28 16:13:42 +05:30
Vineet Gupta aa0efcde45 ARCv2: smp: [plat-*]: No need to explicitly call mcip_init_smp()
MCIP now registers it's own per cpu setup routine (for IPI IRQ request)
using smp_ops.init_irq_cpu().

So no need for platforms to do that. This now completely decouples
platforms from MCIP.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-28 16:13:41 +05:30
Vineet Gupta 286130ebf1 ARC: smp: Introduce smp hook @init_irq_cpu called for all cores
Note this is not part of platform owned static machine_desc,
but more of device owned plat_smp_ops (rather misnamed) which a IPI
provider or some such typically defines.

This will help us seperate out the IPI registration from platform
specific init_cpu_smp() into device specific init_irq_cpu()

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-28 16:13:41 +05:30
Vineet Gupta 8721a7f5a6 ARC: smp: Rename platform hook @init_smp -> @init_cpu_smp
This conveys better that it is called for each cpu

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-28 16:13:40 +05:30
Vineet Gupta 26b8f99623 ARCv2: smp: [plat-*]: No need to explicitly call mcip_init_early_smp()
MCIP now registers it's own probe callback with smp_ops.init_early_smp()
which is called by ARC common code, so no need for platforms to do that.

This decouples the platforms and MCIP and helps confine MCIP details
to it's own file.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-28 16:13:40 +05:30
Vineet Gupta e55af4da02 ARC: smp: Introduce smp hook @init_early_smp for Master core
This adds a platform agnostic early SMP init hook which is called on
Master core before calling setup_processor()

  setup_arch()
     smp_init_cpus()
         smp_ops.init_early_smp()
     ...
     setup_processor()

How this helps:
 - Used for one time init of certain SMP centric IP blocks, before
   calling setup_processor() which probes various bits of core,
   possibly including this block

 - Currently platforms need to call this IP block init from their
   init routines, which doesn't make sense as this is specific to ARC
   core and not platform and otherwise requires copy/paste in all
   (and hence a possible point of failure)

e.g. MCIP init is called from 2 platforms currently (axs10x and sim)
which will go away once we have this.

This change only adds the hooks but they are empty for now. Next commit
will populate them and remove the explicit init calls from platforms.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-28 16:13:40 +05:30
Vineet Gupta 4c82f28617 ARC: remove @init_time, @init_irq platform callbacks
These are not in use for ARC platforms. Moreover DT mechanims exist to
probe them w/o explicit platform calls.

 - clocksource drivers can use CLOCKSOURCE_OF_DECLARE()
 - intc IRQCHIP_DECLARE() calls + cascading inside DT allows external
   intc to be probed automatically

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-28 16:13:39 +05:30
Vineet Gupta e0868e6f67 ARC: smp: irqchip: handle IPI as percpu irq like timer
The reason this was not done so far was lack of genuine IPI_IRQ for
ARC700, as we don't have a SMP version of core yet (which might change
soon thx to EZChip). Nevertheles to increase the build coverage, we
need to allow CONFIG_SMP for ARC700 and still be able to run it on a
UP platform (nsim or AXS101) with a UP Device Tree (SMP-on-UP)

The build itself requires some define for IPI_IRQ and even a dummy
value is fine since that code won't run anyways.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-28 16:13:39 +05:30
Vineet Gupta 3971cdc202 ARC: boot: Support Halt-on-reset and Run-on-reset SMP booting modes
For Run-on-reset, non masters need to spin wait. For Halt-on-reset they
can jump to entry point directly.

Also while at it, made reset vector handler as "the" entry point for
kernel including host debugger based boot (which uses the ELF header
entry point)

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-28 16:08:17 +05:30
Rob Herring b83abc8c2c arc: enable building of all dtbs
Enable building all dtb files when CONFIG_OF_ALL_DTBS is enabled. The dtbs
are not really dependent on a platform being enabled or any other kernel
config, so for testing coverage it is convenient to build all of the dtbs.
This builds all dts files in the tree, not just targets listed.

Signed-off-by: Rob Herring <robh@kernel.org>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-27 16:12:13 -05:00
Rob Herring 10375ccc67 arc: use common make variables for dtb builds
Use dtb-y and always make variables to build dtbs instead of explicit
dtbs rule. This is in preparation to support building all dtbs.

Signed-off-by: Rob Herring <robh@kernel.org>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-27 16:12:13 -05:00
Shawn Lin 005a5243aa arc: axs10x_defconfig: remove CONFIG_MMC_DW_IDMAC
DesignWare MMC Controller's transfer mode should be decided
at runtime instead of compile-time. So we remove this config
option and read dw_mmc's register to select DMA master.

Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2015-10-26 16:00:17 +01:00
Vineet Gupta f33e9c434b ARC: smp: Move default boot kick/wait code out of MCIP into common code
For non halt-on-reset case, all cores start of simultaneously in @stext.
Master core0 proceeds with kernel boot, while other spin-wait on
@wake_flag being set by master once it is ready. So NO hardware assist
is needed for master to "kick" the others.

This patch moves this soft implementation out of mcip.c (as there is no
hardware assist) into common smp.c

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-17 17:48:27 +05:30
Vineet Gupta d0890ea5b6 ARC: boot log: decode more mmu config items
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-17 17:48:26 +05:30
Vineet Gupta 964cf28f9d ARC: boot log: move helper macros to header for reuse
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-17 17:48:25 +05:30
Vineet Gupta b598e17f6a ARC: mm: compute TLB size as needed from ways * sets
This frees up some bits to hold more high level info such as PAE being
present, w/o increasing the size of already bloated cpuinfo struct

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-17 17:48:25 +05:30
Vineet Gupta c583ee4fb0 ARC: mm: MMU v1..v3 only selectable for ARCompact ISA based cores
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-17 17:48:24 +05:30
Vineet Gupta 5c35ee642a ARC: make write_aux_reg safer against macro substitution
It was generating warnings when called as write_aux_reg(x, paddr >> 32)

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-17 17:48:24 +05:30
Vineet Gupta 9fabcc636b ARC: [arcompact] entry.S: Elide extra check/branch in exception ret path
This is done by improving the laddering logic !

Before:

   if Exception
      goto excep_or_pure_k_ret

   if !Interrupt(L2)
      goto l1_chk
   else
      INTERRUPT_EPILOGUE 2

 l1_chk:
   if !Interrupt(L1)  (i.e. pure kernel mode)
      goto excep_or_pure_k_ret
   else
      INTERRUPT_EPILOGUE 1

 excep_or_pure_k_ret:
   EXCEPTION_EPILOGUE

Now:

   if !Interrupt(L1 or L2) (i.e. exception or pure kernel mode)
      goto excep_or_pure_k_ret

  ; guaranteed to be an interrupt
   if !Interrupt(L2)
      goto l1_ret
   else
      INTERRUPT_EPILOGUE 2

 ; by virtue of above, no need to chk for L1 active
 l1_ret:
    INTERRUPT_EPILOGUE 1

 excep_or_pure_k_ret:
    EXCEPTION_EPILOGUE

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-17 17:48:23 +05:30
Vineet Gupta 5f88808745 ARC: [arcompact] entry.S: Document preemption games for L2 intr
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-17 17:48:23 +05:30
Vineet Gupta 55a2ae775a ARC: [arcompact] entry.S: Improve early return from exception
The requirement is to
 - Reenable Exceptions (AE cleared)
 - Reenable Interrupts (E1/E2 set)

We need to do wiggle these bits into ERSTATUS and call RTIE.

Prev version used the pre-exception STATUS32 as starting point for what
goes into ERSTATUS. This required explicit fixups of U/DE/L bits.

Instead, use the current (in-exception) STATUS32 as starting point.
Being in exception handler U/DE/L can be safely assumed to be correct.
Only AE/E1/E2 need to be fixed.

So the new implementation is slightly better
 -Avoids read form memory
 -Is 4 bytes smaller for the typical 1 level of intr configuration
 -Depicts the semantics more clearly

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-17 17:48:22 +05:30
Vineet Gupta 9dbd3d9bfd ARC: [arcompact] don't check for hard isr calling local_irq_enable()
Historically this was done by ARC IDE driver, which is long gone.
IRQ core is pretty robust now and already checks if IRQs are enabled
in hard ISRs. Thus no point in checking this in arch code, for every
call of irq enabled.

Further if some driver does do that - let it bring down the system so we
notice/fix this sooner than covering up for sucker

This makes local_irq_enable() - for L1 only case atleast simple enough
so we can inline it.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-17 17:48:22 +05:30
Vineet Gupta c7119d56d2 ARCv2: mm: THP: flush_pmd_tlb_range make SMP safe
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-17 17:48:21 +05:30
Vineet Gupta 722fe8fd36 ARCv2: mm: THP: Implement flush_pmd_tlb_range() optimization
Implement the TLB flush routine to evict a sepcific Super TLB entry,
vs. moving to a new ASID on every such flush.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-17 17:48:21 +05:30
Vineet Gupta 6ce187985f ARCv2: mm: THP: boot validation/reporting
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-17 17:48:18 +05:30
Vineet Gupta fe6c1b8611 ARCv2: mm: THP support
MMUv4 in HS38x cores supports Super Pages which are basis for Linux THP
support.

Normal and Super pages can co-exist (ofcourse not overlap) in TLB with a
new bit "SZ" in TLB page desciptor to distinguish between them.
Super Page size is configurable in hardware (4K to 16M), but fixed once
RTL builds.

The exact THP size a Linx configuration will support is a function of:
 - MMU page size (typical 8K, RTL fixed)
 - software page walker address split between PGD:PTE:PFN (typical
   11:8:13, but can be changed with 1 line)

So for above default, THP size supported is 8K * 256 = 2M

Default Page Walker is 2 levels, PGD:PTE:PFN, which in THP regime
reduces to 1 level (as PTE is folded into PGD and canonically referred
to as PMD).

Thus thp PMD accessors are implemented in terms of PTE (just like sparc)

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-17 17:48:18 +05:30
Vineet Gupta 24830fc782 ARC: mm: Introduce PTE_SPECIAL
Needed for THP, but will also come in handy for fast GUP later

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-09 17:04:23 +05:30
Vineet Gupta 129cbed54a ARC: mm: pte flags comsetic cleanups, comments
No semantical changes

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-09 17:04:22 +05:30
Vineet Gupta e8a75963a4 ARC: mm: switch pgtable_to to pte_t *
ARC is the only arch with unsigned long type (vs. struct page *).
Historically this was done to avoid the page_address() calls in various
arch hooks which need to get the virtual/logical address of the table.

Some arches alternately define it as pte_t *, and is as efficient as
unsigned long (generated code doesn't change)

Suggested-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-09 17:04:22 +05:30
Ingo Molnar 82fc167c39 Linux 4.3-rc4
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Merge tag 'v4.3-rc4' into locking/core, to pick up fixes before applying new changes

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-06 17:10:28 +02:00
Linus Torvalds 30c44659f4 Merge branch 'strscpy' of git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile
Pull strscpy string copy function implementation from Chris Metcalf.

Chris sent this during the merge window, but I waffled back and forth on
the pull request, which is why it's going in only now.

The new "strscpy()" function is definitely easier to use and more secure
than either strncpy() or strlcpy(), both of which are horrible nasty
interfaces that have serious and irredeemable problems.

strncpy() has a useless return value, and doesn't NUL-terminate an
overlong result.  To make matters worse, it pads a short result with
zeroes, which is a performance disaster if you have big buffers.

strlcpy(), by contrast, is a mis-designed "fix" for strlcpy(), lacking
the insane NUL padding, but having a differently broken return value
which returns the original length of the source string.  Which means
that it will read characters past the count from the source buffer, and
you have to trust the source to be properly terminated.  It also makes
error handling fragile, since the test for overflow is unnecessarily
subtle.

strscpy() avoids both these problems, guaranteeing the NUL termination
(but not excessive padding) if the destination size wasn't zero, and
making the overflow condition very obvious by returning -E2BIG.  It also
doesn't read past the size of the source, and can thus be used for
untrusted source data too.

So why did I waffle about this for so long?

Every time we introduce a new-and-improved interface, people start doing
these interminable series of trivial conversion patches.

And every time that happens, somebody does some silly mistake, and the
conversion patch to the improved interface actually makes things worse.
Because the patch is mindnumbing and trivial, nobody has the attention
span to look at it carefully, and it's usually done over large swatches
of source code which means that not every conversion gets tested.

So I'm pulling the strscpy() support because it *is* a better interface.
But I will refuse to pull mindless conversion patches.  Use this in
places where it makes sense, but don't do trivial patches to fix things
that aren't actually known to be broken.

* 'strscpy' of git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile:
  tile: use global strscpy() rather than private copy
  string: provide strscpy()
  Make asm/word-at-a-time.h available on all architectures
2015-10-04 16:31:13 +01:00
Peter Zijlstra 62e8a3258b atomic, arch: Audit atomic_{read,set}()
This patch makes sure that atomic_{read,set}() are at least
{READ,WRITE}_ONCE().

We already had the 'requirement' that atomic_read() should use
ACCESS_ONCE(), and most archs had this, but a few were lacking.
All are now converted to use READ_ONCE().

And, by a symmetry and general paranoia argument, upgrade atomic_set()
to use WRITE_ONCE().

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: james.hogan@imgtec.com
Cc: linux-kernel@vger.kernel.org
Cc: oleg@redhat.com
Cc: will.deacon@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-09-23 09:54:28 +02:00
Thomas Gleixner bd0b9ac405 genirq: Remove irq argument from irq flow handlers
Most interrupt flow handlers do not use the irq argument. Those few
which use it can retrieve the irq number from the irq descriptor.

Remove the argument.

Search and replace was done with coccinelle and some extra helper
scripts around it. Thanks to Julia for her help!

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Julia Lawall <Julia.Lawall@lip6.fr>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
2015-09-16 15:47:51 +02:00
Vineet Gupta 3ebb0540c2 ARCv2: [axs103_smp] Reduce clk for SMP FPGA configs
Newer bitfiles needs the reduced clk even for SMP builds

Cc: <stable@vger.kernel.org>  #4.2
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-11 19:34:01 -07:00
Linus Torvalds ca520cab25 Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking and atomic updates from Ingo Molnar:
 "Main changes in this cycle are:

   - Extend atomic primitives with coherent logic op primitives
     (atomic_{or,and,xor}()) and deprecate the old partial APIs
     (atomic_{set,clear}_mask())

     The old ops were incoherent with incompatible signatures across
     architectures and with incomplete support.  Now every architecture
     supports the primitives consistently (by Peter Zijlstra)

   - Generic support for 'relaxed atomics':

       - _acquire/release/relaxed() flavours of xchg(), cmpxchg() and {add,sub}_return()
       - atomic_read_acquire()
       - atomic_set_release()

     This came out of porting qwrlock code to arm64 (by Will Deacon)

   - Clean up the fragile static_key APIs that were causing repeat bugs,
     by introducing a new one:

       DEFINE_STATIC_KEY_TRUE(name);
       DEFINE_STATIC_KEY_FALSE(name);

     which define a key of different types with an initial true/false
     value.

     Then allow:

       static_branch_likely()
       static_branch_unlikely()

     to take a key of either type and emit the right instruction for the
     case.  To be able to know the 'type' of the static key we encode it
     in the jump entry (by Peter Zijlstra)

   - Static key self-tests (by Jason Baron)

   - qrwlock optimizations (by Waiman Long)

   - small futex enhancements (by Davidlohr Bueso)

   - ... and misc other changes"

* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (63 commits)
  jump_label/x86: Work around asm build bug on older/backported GCCs
  locking, ARM, atomics: Define our SMP atomics in terms of _relaxed() operations
  locking, include/llist: Use linux/atomic.h instead of asm/cmpxchg.h
  locking/qrwlock: Make use of _{acquire|release|relaxed}() atomics
  locking/qrwlock: Implement queue_write_unlock() using smp_store_release()
  locking/lockref: Remove homebrew cmpxchg64_relaxed() macro definition
  locking, asm-generic: Add _{relaxed|acquire|release}() variants for 'atomic_long_t'
  locking, asm-generic: Rework atomic-long.h to avoid bulk code duplication
  locking/atomics: Add _{acquire|release|relaxed}() variants of some atomic operations
  locking, compiler.h: Cast away attributes in the WRITE_ONCE() magic
  locking/static_keys: Make verify_keys() static
  jump label, locking/static_keys: Update docs
  locking/static_keys: Provide a selftest
  jump_label: Provide a self-test
  s390/uaccess, locking/static_keys: employ static_branch_likely()
  x86, tsc, locking/static_keys: Employ static_branch_likely()
  locking/static_keys: Add selftest
  locking/static_keys: Add a new static_key interface
  locking/static_keys: Rework update logic
  locking/static_keys: Add static_key_{en,dis}able() helpers
  ...
2015-09-03 15:46:07 -07:00
Linus Torvalds 17e6b00ac4 Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq updates from Thomas Gleixner:
 "This updated pull request does not contain the last few GIC related
  patches which were reported to cause a regression.  There is a fix
  available, but I let it breed for a couple of days first.

  The irq departement provides:

   - new infrastructure to support non PCI based MSI interrupts
   - a couple of new irq chip drivers
   - the usual pile of fixlets and updates to irq chip drivers
   - preparatory changes for removal of the irq argument from interrupt
     flow handlers
   - preparatory changes to remove IRQF_VALID"

* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (129 commits)
  irqchip/imx-gpcv2: IMX GPCv2 driver for wakeup sources
  irqchip: Add bcm2836 interrupt controller for Raspberry Pi 2
  irqchip: Add documentation for the bcm2836 interrupt controller
  irqchip/bcm2835: Add support for being used as a second level controller
  irqchip/bcm2835: Refactor handle_IRQ() calls out of MAKE_HWIRQ
  PCI: xilinx: Fix typo in function name
  irqchip/gic: Ensure gic_cpu_if_up/down() programs correct GIC instance
  irqchip/gic: Only allow the primary GIC to set the CPU map
  PCI/MSI: pci-xgene-msi: Consolidate chained IRQ handler install/remove
  unicore32/irq: Prepare puv3_gpio_handler for irq argument removal
  tile/pci_gx: Prepare trio_handle_level_irq for irq argument removal
  m68k/irq: Prepare irq handlers for irq argument removal
  C6X/megamode-pic: Prepare megamod_irq_cascade for irq argument removal
  blackfin: Prepare irq handlers for irq argument removal
  arc/irq: Prepare idu_cascade_isr for irq argument removal
  sparc/irq: Use access helper irq_data_get_affinity_mask()
  sparc/irq: Use helper irq_data_get_irq_handler_data()
  parisc/irq: Use access helper irq_data_get_affinity_mask()
  mn10300/irq: Use access helper irq_data_get_affinity_mask()
  irqchip/i8259: Prepare i8259_irq_dispatch for irq argument removal
  ...
2015-09-01 14:33:35 -07:00
Vineet Gupta 3d5926599a ARCv2: entry: Fix reserved handler
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-27 16:25:37 +05:30
Vineet Gupta 9b28829d6d ARCv2: perf: Finally introduce HS perf unit
With all features in place, the ARC HS pct block can now be effectively
allowed to be probed/used

Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-27 14:59:07 +05:30
Alexey Brodkin e525c37f84 ARCv2: perf: SMP support
* split off pmu info into singleton and per-cpu bits
* setup PMU on all cores

Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-27 14:58:42 +05:30
Alexey Brodkin e6b1d126bb ARCv2: perf: implement exclusion of event counting in user or kernel mode
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-27 14:58:14 +05:30
Alexey Brodkin 36481cf7fb ARCv2: perf: Support sampling events using overflow interrupts
In times of ARC 700 performance counters didn't have support of
interrupt an so for ARC we only had support of non-sampling events.

Put simply only "perf stat" was functional.

Now with ARC HS we have support of interrupts in performance counters
which this change introduces support of.

ARC performance counters act in the following way in regard of
interrupts generation.
 [1] A counter counts starting from value set in PCT_COUNT register pair
 [2] Once counter reaches value set in PCT_INT_CNT interrupt is raised

Basic setup look like this:
 [1] PCT_COUNT = 0;
 [2] PCT_INT_CNT = __limit_value__;
 [3] Enable interrupts for that counter and let it run
 [4] Let counter reach its limit
 [5] Handle interrupt when it happens

Note that PCT HW block is build in CPU core and so ints interrupt
line (which is basically OR of all counters IRQs) is wired directly to
top-level IRQC. That means do de-assert PCT interrupt it's required to
reset IRQs from all counters that have reached their limit values.

Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-27 14:57:43 +05:30
Alexey Brodkin 1fe8bfa5ff ARCv2: perf: implement "event_set_period"
This generalization prepares for support of overflow interrupts.

Hardware event counters on ARC work that way:
Each counter counts from programmed start value (set in
ARC_REG_PCT_COUNT) to a limit value (set in ARC_REG_PCT_INT_CNT) and
once limit value is reached this timer generates an interrupt.

Even though this hardware implementation allows for more flexibility,
in Linux kernel we decided to mimic behavior of other architectures
this way:

 [1] Set limit value as half of counter's max value (to allow counter to
     run after reaching it limit, see below for more explanation):
 ---------->8-----------
 arc_pmu->max_period = (1ULL << counter_size) / 2 - 1ULL;
 ---------->8-----------

 [2] Set start value as "arc_pmu->max_period - sample_period" and then
count up to the limit

Our event counters don't stop on reaching max value (the one we set in
ARC_REG_PCT_INT_CNT) but continue to count until kernel explicitly
stops each of them.

And setting a limit as half of counter capacity is done to allow
capturing of additional events in between moment when interrupt was
triggered until we're actually processing PMU interrupts. That way
we're trying to be more precise.

For example if we count CPU cycles we keep track of cycles while
running through generic IRQ handling code:

 [1] We set counter period as say 100_000 events of type "crun"
 [2] Counter reaches that limit and raises its interrupt
 [3] Once we get in PMU IRQ handler we read current counter value from
ARC_REG_PCT_SNAP ans see there something like 105_000.

If counters stop on reaching a limit value then we would miss
additional 5000 cycles.

Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-27 14:57:29 +05:30
Vineet Gupta fb7c572551 ARC: perf: cap the number of counters to hardware max of 32
The number of counters in PCT can never be more than 32 (while
countable conditions could be 100+) for both ARCompact and ARCv2

And while at it update copyright dates.

Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-27 14:57:03 +05:30
Vineet Gupta fd0881a24a ARC: Eliminate some ARCv2 specific code for ARCompact build
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-21 15:06:43 +05:30
Vineet Gupta 090749502f ARC: add/fix some comments in code - no functional change
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-20 19:05:49 +05:30
Yuriy Kolerov 6de6066c0d ARC: change some branchs to jumps to resolve linkage errors
When kernel's binary becomes large enough (32M and more) errors
may occur during the final linkage stage. It happens because
the build system uses short relocations for ARC  by default.
This problem may be easily resolved by passing -mlong-calls
option to GCC to use long absolute jumps (j) instead of short
relative branchs (b).

But there are fragments of pure assembler code exist which use
branchs in inappropriate places and cause a linkage error because
of relocations overflow.

First of these fragments is .fixup insertion in futex.h and
unaligned.c. It inserts a code in the separate section (.fixup)
with branch instruction. It leads to the linkage error when
kernel becomes large.

Second of these fragments is calling scheduler's functions
(common kernel code) from entry.S of ARC's code. When kernel's
binary becomes large it may lead to the linkage error because
scheduler may occur far enough from ARC's code in the final
binary.

Signed-off-by: Yuriy Kolerov <yuriy.kolerov@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-20 18:53:15 +05:30
Vineet Gupta eb2cd8b72b ARC: ensure futex ops are atomic in !LLSC config
W/o hardware assisted atomic r-m-w the best we can do is to disable
preemption.

Cc: David Hildenbrand <dahi@linux.vnet.ibm.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Michel Lespinasse <walken@google.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-20 18:16:01 +05:30
Vineet Gupta 5e0574292a ARC: Enable HAVE_FUTEX_CMPXCHG
ARC doesn't need the runtime detection of futex cmpxchg op

Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-20 18:16:01 +05:30
Vineet Gupta 882a95ae0a ARC: make futex_atomic_cmpxchg_inatomic() return bimodal
Callers of cmpxchg_futex_value_locked() in futex code expect bimodal
return value:
  !0 (essentially -EFAULT as failure)
   0 (success)

Before this patch, the success return value was old value of futex,
which could very well be non zero, causing caller to possibly take the
failure path erroneously.

Fix that by returning 0 for success

(This fix was done back in 2011 for all upstream arches, which ARC
obviously missed)

Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Michel Lespinasse <walken@google.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-20 18:16:00 +05:30
Vineet Gupta ed574e2bbd ARC: futex cosmetics
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Michel Lespinasse <walken@google.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-20 18:16:00 +05:30
Vineet Gupta 31d30c8208 ARC: add barriers to futex code
The atomic ops on futex need to provide the full barrier just like
regular atomics in kernel.

Also remove pagefault_enable/disable in futex_atomic_cmpxchg_inatomic()
as core code already does that

Cc: David Hildenbrand <dahi@linux.vnet.ibm.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Michel Lespinasse <walken@google.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-20 18:15:59 +05:30
Alexey Brodkin 1648c70d30 ARCv2: IOC: Allow boot time disable
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-20 18:15:31 +05:30
Vineet Gupta 79335a2ca0 ARCv2: SLC: Allow boot time disable
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-20 18:11:52 +05:30
Alexey Brodkin f2b0b25a37 ARCv2: Support IO Coherency and permutations involving L1 and L2 caches
In case of ARCv2 CPU there're could be following configurations
that affect cache handling for data exchanged with peripherals
via DMA:
 [1] Only L1 cache exists
 [2] Both L1 and L2 exist, but no IO coherency unit
 [3] L1, L2 caches and IO coherency unit exist

Current implementation takes care of [1] and [2].
Moreover support of [2] is implemented with run-time check
for SLC existence which is not super optimal.

This patch introduces support of [3] and rework of DMA ops
usage. Instead of doing run-time check every time a particular
DMA op is executed we'll have 3 different implementations of
DMA ops and select appropriate one during init.

As for IOC support for it we need:
 [a] Implement empty DMA ops because IOC takes care of cache
     coherency with DMAed data
 [b] Route dma_alloc_coherent() via dma_alloc_noncoherent()
     This is required to make IOC work in first place and also
     serves as optimization as LD/ST to coherent buffers can be
     srviced from caches w/o going all the way to memory

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
[vgupta:
  -Added some comments about IOC gains
  -Marked dma ops as static,
  -Massaged changelog a bit]
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-20 18:11:17 +05:30
Vineet Gupta 2a4401687c ARC: Enable optimistic spinning for LLSC config
Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-11 14:51:09 +05:30
Vineet Gupta 1097163870 ARCv2: spinlock/rwlock/atomics: reduce 1 instruction in exponential backoff
The increment of delay counter was 2 instructions:
Arithmatic Shfit Left (ASL) + set to 1 on overflow

This can be done in 1 using ROtate Left (ROL)

Suggested-by: Nigel Topham <ntopham@synopsys.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-07 13:56:16 +05:30
Vineet Gupta 87ce62802f ARC: Make pt_regs regs unsigned
KGDB fails to build after f51e2f1911 ("ARC: make sure instruction_pointer()
returns unsigned value")

The hack to force one specific reg to unsigned backfired. There's no
reason to keep the regs signed after all.

|  CC      arch/arc/kernel/kgdb.o
|../arch/arc/kernel/kgdb.c: In function 'kgdb_trap':
| ../arch/arc/kernel/kgdb.c:180:29: error: lvalue required as left operand of assignment
|   instruction_pointer(regs) -= BREAK_INSTR_SIZE;

Reported-by: Yuriy Kolerov <yuriy.kolerov@synopsys.com>
Fixes: f51e2f1911 ("ARC: make sure instruction_pointer() returns unsigned value")
Cc: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-05 11:48:21 +05:30
Vineet Gupta b89aa12c17 ARCv2: spinlock/rwlock: Reset retry delay when starting a new spin-wait cycle
The previous commit for delayed retry of SCOND needs some fine tuning
for spin locks.

The backoff from delayed retry in conjunction with spin looping of lock
itself can potentially cause the delay counter to reach high values.
So to provide fairness to any lock operation, after a lock "seems"
available (i.e. just before first SCOND try0, reset the delay counter
back to starting value of 1

Essentially reset delay to 1 for a new spin-wait-loop-acquire cycle.

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-04 09:26:35 +05:30
Vineet Gupta e78fdfef84 ARCv2: spinlock/rwlock/atomics: Delayed retry of failed SCOND with exponential backoff
This is to workaround the llock/scond livelock

HS38x4 could get into a LLOCK/SCOND livelock in case of multiple overlapping
coherency transactions in the SCU. The exclusive line state keeps rotating
among contenting cores leading to a never ending cycle. So break the cycle
by deferring the retry of failed exclusive access (SCOND). The actual delay
needed is function of number of contending cores as well as the unrelated
coherency traffic from other cores. To keep the code simple, start off with
small delay of 1 which would suffice most cases and in case of contention
double the delay. Eventually the delay is sufficient such that the coherency
pipeline is drained, thus a subsequent exclusive access would succeed.

Link: http://lkml.kernel.org/r/1438612568-28265-1-git-send-email-vgupta@synopsys.com
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-04 09:26:34 +05:30
Vineet Gupta 69cbe630f5 ARC: LLOCK/SCOND based rwlock
With LLOCK/SCOND, the rwlock counter can be atomically updated w/o need
for a guarding spin lock.

This in turn elides the EXchange instruction based spinning which causes
the cacheline transition to exclusive state and concurrent spinning
across cores would cause the line to keep bouncing around.
LLOCK/SCOND based implementation is superior as spinning on LLOCK keeps
the cacheline in shared state.

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-04 09:26:33 +05:30
Vineet Gupta ae7eae9e03 ARC: LLOCK/SCOND based spin_lock
Current spin_lock uses EXchange instruction to implement the atomic test
and set of lock location (reads orig value and ST 1). This however forces
the cacheline into exclusive state (because of the ST) and concurrent
loops in multiple cores will bounce the line around between cores.

Instead, use LLOCK/SCOND to implement the atomic test and set which is
better as line is in shared state while lock is spinning on LLOCK

The real motivation of this change however is to make way for future
changes in atomics to implement delayed retry (with backoff).
Initial experiment with delayed retry in atomics combined with orig
EX based spinlock was a total disaster (broke even LMBench) as
struct sock has a cache line sharing an atomic_t and spinlock. The
tight spinning on lock, caused the atomic retry to keep backing off
such that it would never finish.

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-04 09:26:33 +05:30
Vineet Gupta 8ac0665fb6 ARC: refactor atomic inline asm operands with symbolic names
This reduces the diff in forth-coming patches and also helps understand
better the incremental changes to inline asm.

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-04 09:26:32 +05:30
Vineet Gupta f5959cb0c3 Revert "ARCv2: STAR 9000837815 workaround hardware exclusive transactions livelock"
Extended testing of quad core configuration revealed that this fix was
insufficient. Specifically LTP open posix shm_op/23-1 would cause the
hardware livelock in llock/scond loop in update_cpu_load_active()

So remove this and make way for a proper workaround

This reverts commit a5c8b52abe.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-04 09:26:31 +05:30
Vineet Gupta 6de7abfbad ARCv2: [axs103_smp] Reduce clk for Quad FPGA configs
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-04 09:26:30 +05:30
Vineet Gupta e13c42ecbe ARCv2: Fix the peripheral address space detection
With HS 2.1 release, the peripheral space register no longer contains
the uncached space specifics, causing the kernel to panic early on.
So read the newer NON VOLATILE AUX register to get that info.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-03 19:34:07 +05:30
Thomas Gleixner badae6bc94 arc/irq: Prepare idu_cascade_isr for irq argument removal
The irq argument of most interrupt flow handlers is unused or merily
used instead of a local variable. The handlers which need the irq
argument can retrieve the irq number from the irq descriptor.

Search and update was done with coccinelle and the invaluable help of
Julia Lawall.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Julia Lawall <Julia.Lawall@lip6.fr>
Cc: Vineet Gupta <vgupta@synopsys.com>
2015-07-31 22:20:05 +02:00
Peter Zijlstra de9e432cb5 atomic: Collapse all atomic_{set,clear}_mask definitions
Move the now generic definitions of atomic_{set,clear}_mask() into
linux/atomic.h to avoid endless and pointless repetition.

Also, provide an atomic_andnot() wrapper for those few archs that can
implement that.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-07-27 14:06:24 +02:00
Peter Zijlstra e6942b7de2 atomic: Provide atomic_{or,xor,and}
Implement atomic logic ops -- atomic_{or,xor,and}.

These will replace the atomic_{set,clear}_mask functions that are
available on some archs.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-07-27 14:06:24 +02:00
Peter Zijlstra cda7e4137a arc: Provide atomic_{or,xor,and}
Implement atomic logic ops -- atomic_{or,xor,and}.

These will replace the atomic_{set,clear}_mask functions that are
available on some archs.

Acked-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-07-27 14:06:21 +02:00
Alexey Brodkin 450ed0db01 ARCv2: allow selection of page size for MMUv4
MMUv4 also supports the configurable page size as MMUv3.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-07-23 12:04:39 +03:00
Vineet Gupta 262137bca7 ARCv2: lib: memset: Don't assume 64-bit load/stores
There are configurations which may not have LDD/STD

Signed-off-by: Claudiu Zissulescu <claziss@synopsys.com>
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-07-20 17:44:37 +03:00
Vineet Gupta 21481f2cfe ARCv2: lib: memcpy: Missing PREFETCHW
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-07-20 17:27:35 +03:00
Alexey Brodkin d05a76ab4d ARCv2: add knob for DIV_REV in Kconfig
Being highly configurable core ARC HS among other features might be
configured with or without DIV_REM_OPTION (hardware divider).

That option when enabled adds following instructions: div, divu, rem, remu.

By default ARC HS38 has this option enabled. So we add here possibility
to disable usage of hardware divider by compiler.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-07-20 13:33:30 +03:00
Viresh Kumar aeec6cdad6 ARC/time: Migrate to new 'set-state' interface
Migrate arc driver to the new 'set-state' interface provided by
clockevents core, the earlier 'set-mode' interface is marked obsolete
now.

This also enables us to implement callbacks for new states of clockevent
devices, for example: ONESHOT_STOPPED.

Cc: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-07-20 13:30:31 +03:00
Laurent Dufour f2abeef9fd mm: clean up per architecture MM hook header files
Commit 2ae416b142 ("mm: new mm hook framework") introduced an empty
header file (mm-arch-hooks.h) for every architecture, even those which
doesn't need to define mm hooks.

As suggested by Geert Uytterhoeven, this could be cleaned through the use
of a generic header file included via each per architecture
asm/include/Kbuild file.

The PowerPC architecture is not impacted here since this architecture has
to defined the arch_remap MM hook.

Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Suggested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-07-17 16:39:53 -07:00
Vineet Gupta 624b71ee20 ARCv2: support HS38 releases
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-07-13 13:33:23 +05:30
Alexey Brodkin f51e2f1911 ARC: make sure instruction_pointer() returns unsigned value
Currently instruction_pointer() returns pt_regs->ret and so return value
is of type "long", which implicitly stands for "signed long".

While that's perfectly fine when dealing with 32-bit values if return
value of instruction_pointer() gets assigned to 64-bit variable sign
extension may happen.

And at least in one real use-case it happens already.
In perf_prepare_sample() return value of perf_instruction_pointer()
(which is an alias to instruction_pointer() in case of ARC) is assigned
to (struct perf_sample_data)->ip (which type is "u64").

And what we see if instuction pointer points to user-space application
that in case of ARC lays below 0x8000_0000 "ip" gets set properly with
leading 32 zeros. But if instruction pointer points to kernel address
space that starts from 0x8000_0000 then "ip" is set with 32 leadig
"f"-s. I.e. id instruction_pointer() returns 0x8100_0000, "ip" will be
assigned with 0xffff_ffff__8100_0000. Which is obviously wrong.

In particular that issuse broke output of perf, because perf was unable
to associate addresses like 0xffff_ffff__8100_0000 with anything from
/proc/kallsyms.

That's what we used to see:
 ----------->8----------
  6.27%  ls       [unknown]                [k] 0xffffffff8046c5cc
  2.96%  ls       libuClibc-0.9.34-git.so  [.] memcpy
  2.25%  ls       libuClibc-0.9.34-git.so  [.] memset
  1.66%  ls       [unknown]                [k] 0xffffffff80666536
  1.54%  ls       libuClibc-0.9.34-git.so  [.] 0x000224d6
  1.18%  ls       libuClibc-0.9.34-git.so  [.] 0x00022472
 ----------->8----------

With that change perf output looks much better now:
 ----------->8----------
  8.21%  ls       [kernel.kallsyms]        [k] memset
  3.52%  ls       libuClibc-0.9.34-git.so  [.] memcpy
  2.11%  ls       libuClibc-0.9.34-git.so  [.] malloc
  1.88%  ls       libuClibc-0.9.34-git.so  [.] memset
  1.64%  ls       [kernel.kallsyms]        [k] _raw_spin_unlock_irqrestore
  1.41%  ls       [kernel.kallsyms]        [k] __d_lookup_rcu
 ----------->8----------

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: arc-linux-dev@synopsys.com
Cc: stable@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-07-13 13:33:18 +05:30
Vineet Gupta b631788ab4 ARC: slightly refactor macros for boot logging
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-07-09 17:36:33 +05:30
Vineet Gupta 9138d4138d ARC: Add llock/scond to futex backend
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-07-09 17:36:33 +05:30
Joël Porquet 70d93d8941 arc:irqchip: prepare for drivers/irqchip/irqchip.h removal
The IRQCHIP_DECLARE macro migrated to 'include/linux/irqchip.h'.

See commit 91e20b5040
("irqchip: Move IRQCHIP_DECLARE macro to include/linux/irqchip.h").

This patch removes the inclusions of private header 'drivers/irqchip/irqchip.h'
and if necessary replaces them with inclusions of 'include/linux/irqchip.h'.

Signed-off-by: Joel Porquet <joel@porquet.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-07-09 17:36:32 +05:30
Vineet Gupta 80f420842f ARC: Make ARC bitops "safer" (add anti-optimization)
ARCompact/ARCv2 ISA provide that any instructions which deals with
bitpos/count operand ASL, LSL, BSET, BCLR, BMSK .... will only consider
lower 5 bits. i.e. auto-clamp the pos to 0-31.

ARC Linux bitops exploited this fact by NOT explicitly masking out upper
bits for @nr operand in general, saving a bunch of AND/BMSK instructions
in generated code around bitops.

While this micro-optimization has worked well over years it is NOT safe
as shifting a number with a value, greater than native size is
"undefined" per "C" spec.

So as it turns outm EZChip ran into this eventually, in their massive
muti-core SMP build with 64 cpus. There was a test_bit() inside a loop
from 63 to 0 and gcc was weirdly optimizing away the first iteration
(so it was really adhering to standard by implementing undefined behaviour
vs. removing all the iterations which were phony i.e. (1 << [63..32])

| for i = 63 to 0
|    X = ( 1 << i )
|    if X == 0
|       continue

So fix the code to do the explicit masking at the expense of generating
additional instructions. Fortunately, this can be mitigated to a large
extent as gcc has SHIFT_COUNT_TRUNCATED which allows combiner to fold
masking into shift operation itself. It is currently not enabled in ARC
gcc backend, but could be done after a bit of testing.

Fixes STAR 9000866918 ("unsafe "undefined behavior" code in kernel")

Reported-by: Noam Camus <noamc@ezchip.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-07-09 17:36:32 +05:30
Alexey Brodkin e2fc61f384 ARCv2: [axs103] bump CPU frequency from 75 to 90 MHZ
With up-to-date FPGA builds ARC cores are supposed to correctly operate
even with 90 MHz clock (which is a target frequency for AXS103 release).

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: arc-linux-dev@synopsys.com
2015-07-09 17:36:31 +05:30
Chris Metcalf a6e2f029ae Make asm/word-at-a-time.h available on all architectures
Added the x86 implementation of word-at-a-time to the
generic version, which previously only supported big-endian.

Omitted the x86-specific load_unaligned_zeropad(), which in
any case is also not present for the existing BE-only
implementation of a word-at-a-time, and is only used under
CONFIG_DCACHE_WORD_ACCESS.

Added as a "generic-y" to the Kbuilds of all architectures
that didn't previously have it.

Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com>
2015-07-08 16:41:55 -04:00
Vineet Gupta 6b12ec177c ARCv2: intc: IDU: Fix potential race in installing a chained IRQ handler
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-07-06 11:09:06 +05:30
Vineet Gupta 83ce3e6fcc ARCv2: intc: IDU: support irq affinity
With this nsim standlone / OSCI have working irq affinity - AXS103 still
needs some work as IDU is not visible in intc hierarchy yet !

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-07-06 11:09:02 +05:30
Vineet Gupta bccea41ec0 ARC: fix unused var wanring
Fixes: 9bf39ab2ad ("vfs: add file_path() helper")
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-07-06 11:09:01 +05:30
Vineet Gupta f718c2efff ARC: Don't memzero twice in dma_alloc_coherent for __GFP_ZERO
alloc_pages_exact() get gfp flags and handle zero'ing already

And while it, fix the case where ioremap fails: return rightaway.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-07-06 11:09:01 +05:30
Vineet Gupta 9770906921 ARC: Override toplevel default -O2 with -O3
ARC kernels have historically been built with -O3, despite top level
Makefile defaulting to -O2. This was facilitated by implicitly ordering
of arch makefile include AFTER top level assigned -O2.

An upstream fix to top level a1c48bb160 ("Makefile: Fix unrecognized
cross-compiler command line options") changed the ordering, making ARC
-O3 defunct.

Fix that by NOT relying on any ordering whatsoever and use the proper
arch override facility now present in kbuild (ARCH_*FLAGS)

Depends-on: ("kbuild: Allow arch Makefiles to override {cpp,ld,c}flags")
Suggested-by: Michal Marek <mmarek@suse.cz>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: stable@vger.kernel.org # 3.16+
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-07-06 11:09:00 +05:30
Alexey Brodkin b607eddd71 ARCv2: guard SLC DMA ops with spinlock
SLC maintenance ops need to be serialized by software as there is no
inherent buffering / quequing of aux commands. It can silently ignore a
new aux operation if previous one is still ongoing (SLC_CTRL_BUSY)

So gaurd the SLC op using a spin lock

The spin lock doesn't seem to be contended even in heavy workloads such
as iperf. On FPGA @ 75 MHz.

 [1] Before this change:
 ============================================================
  # iperf -c 10.42.0.1
 ------------------------------------------------------------
 Client connecting to 10.42.0.1, TCP port 5001
 TCP window size: 43.8 KByte (default)
 ------------------------------------------------------------
 [  3] local 10.42.0.110 port 38935 connected with 10.42.0.1 port 5001
 [ ID] Interval       Transfer     Bandwidth
 [  3]  0.0-10.0 sec  48.4 MBytes  40.6 Mbits/sec
 ============================================================

 [2] After this change:
 ============================================================
 # iperf -c 10.42.0.1
 ------------------------------------------------------------
 Client connecting to 10.42.0.1, TCP port 5001
 TCP window size: 43.8 KByte (default)
 ------------------------------------------------------------
 [  3] local 10.42.0.243 port 60248 connected with 10.42.0.1 port 5001
 [ ID] Interval       Transfer     Bandwidth
 [  3]  0.0-10.0 sec  47.5 MBytes  39.8 Mbits/sec
 # iperf -c 10.42.0.1
 ------------------------------------------------------------
 Client connecting to 10.42.0.1, TCP port 5001
 TCP window size: 43.8 KByte (default)
 ------------------------------------------------------------
 [  3] local 10.42.0.243 port 60249 connected with 10.42.0.1 port 5001
 [ ID] Interval       Transfer     Bandwidth
 [  3]  0.0-10.0 sec  54.9 MBytes  46.0 Mbits/sec
 ============================================================

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: arc-linux-dev@synopsys.com
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-07-06 10:12:39 +05:30
Vineet Gupta 14a0abfc4a ARC: Kconfig: better way to disable ARC_HAS_LLSC for ARC_CPU_750D
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-07-06 10:12:39 +05:30
Linus Torvalds 1dc51b8288 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull more vfs updates from Al Viro:
 "Assorted VFS fixes and related cleanups (IMO the most interesting in
  that part are f_path-related things and Eric's descriptor-related
  stuff).  UFS regression fixes (it got broken last cycle).  9P fixes.
  fs-cache series, DAX patches, Jan's file_remove_suid() work"

[ I'd say this is much more than "fixes and related cleanups".  The
  file_table locking rule change by Eric Dumazet is a rather big and
  fundamental update even if the patch isn't huge.   - Linus ]

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (49 commits)
  9p: cope with bogus responses from server in p9_client_{read,write}
  p9_client_write(): avoid double p9_free_req()
  9p: forgetting to cancel request on interrupted zero-copy RPC
  dax: bdev_direct_access() may sleep
  block: Add support for DAX reads/writes to block devices
  dax: Use copy_from_iter_nocache
  dax: Add block size note to documentation
  fs/file.c: __fget() and dup2() atomicity rules
  fs/file.c: don't acquire files->file_lock in fd_install()
  fs:super:get_anon_bdev: fix race condition could cause dev exceed its upper limitation
  vfs: avoid creation of inode number 0 in get_next_ino
  namei: make set_root_rcu() return void
  make simple_positive() public
  ufs: use dir_pages instead of ufs_dir_pages()
  pagemap.h: move dir_pages() over there
  remove the pointless include of lglock.h
  fs: cleanup slight list_entry abuse
  xfs: Correctly lock inode when removing suid and file capabilities
  fs: Call security_ops->inode_killpriv on truncate
  fs: Provide function telling whether file_remove_privs() will do anything
  ...
2015-07-04 19:36:06 -07:00
Linus Torvalds 2d01eedf1d Merge branch 'akpm' (patches from Andrew)
Merge third patchbomb from Andrew Morton:

 - the rest of MM

 - scripts/gdb updates

 - ipc/ updates

 - lib/ updates

 - MAINTAINERS updates

 - various other misc things

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (67 commits)
  genalloc: rename of_get_named_gen_pool() to of_gen_pool_get()
  genalloc: rename dev_get_gen_pool() to gen_pool_get()
  x86: opt into HAVE_COPY_THREAD_TLS, for both 32-bit and 64-bit
  MAINTAINERS: add zpool
  MAINTAINERS: BCACHE: Kent Overstreet has changed email address
  MAINTAINERS: move Jens Osterkamp to CREDITS
  MAINTAINERS: remove unused nbd.h pattern
  MAINTAINERS: update brcm gpio filename pattern
  MAINTAINERS: update brcm dts pattern
  MAINTAINERS: update sound soc intel patterns
  MAINTAINERS: remove website for paride
  MAINTAINERS: update Emulex ocrdma email addresses
  bcache: use kvfree() in various places
  libcxgbi: use kvfree() in cxgbi_free_big_mem()
  target: use kvfree() in session alloc and free
  IB/ehca: use kvfree() in ipz_queue_{cd}tor()
  drm/nouveau/gem: use kvfree() in u_free()
  drm: use kvfree() in drm_free_large()
  cxgb4: use kvfree() in t4_free_mem()
  cxgb3: use kvfree() in cxgb_free_mem()
  ...
2015-07-01 17:47:51 -07:00
Linus Torvalds 0890a26479 - Support for HS38 cores based on ARCv2 ISA
ARCv2 is the next generation ISA from Synopsys and basis for the
      HS3{4,6,8} families of processors which retain the traditional ARC mantra of
      low power and configurability and are now more performant and feature rich.
 
      HS38x is a 10 stage pipeline core which supports MMU (with huge pages) and
      SMP (upto 4 cores) among other features.
 
      + www.synopsys.com/dw/ipdir.php?ds=arc-hs38-processor
      + http://news.synopsys.com/2014-10-14-New-DesignWare-ARC-HS38-Processor-Doubles-Performance-for-Embedded-Linux-Applications
      + http://www.embedded.com/electronics-news/4435975/Synopsys-ARC-HS38-core-gives-2X-boost-to-Linux-based-apps
 
  - Support for ARC SDP (Software Development platform): Main Board + CPU Cards
     = AXS101: CPU Card with ARC700 in silicon @ 700 MHz
     = AXS103: CPU Card with HS38x in FPGA
 
  - Refactoring of ARCompact port to accomodate new ARCv2 ISA
  - Miscll updates/cleanups
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Merge tag 'arc-4.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc

Pull ARC architecture updates from Vineet Gupta:

 - support for HS38 cores based on ARCv2 ISA

     ARCv2 is the next generation ISA from Synopsys and basis for the
     HS3{4,6,8} families of processors which retain the traditional ARC mantra of
     low power and configurability and are now more performant and feature rich.

     HS38x is a 10 stage pipeline core which supports MMU (with huge pages) and
     SMP (upto 4 cores) among other features.

     + www.synopsys.com/dw/ipdir.php?ds=arc-hs38-processor
     + http://news.synopsys.com/2014-10-14-New-DesignWare-ARC-HS38-Processor-Doubles-Performance-for-Embedded-Linux-Applications
     + http://www.embedded.com/electronics-news/4435975/Synopsys-ARC-HS38-core-gives-2X-boost-to-Linux-based-apps

 - support for ARC SDP (Software Development platform): Main Board + CPU Cards
    = AXS101: CPU Card with ARC700 in silicon @ 700 MHz
    = AXS103: CPU Card with HS38x in FPGA

 - refactoring of ARCompact port to accomodate new ARCv2 ISA

 - misc updates/cleanups

* tag 'arc-4.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc: (72 commits)
  ARC: Fix build failures for ARCompact in linux-next after ARCv2 support
  ARCv2: Allow older gcc to cope with new regime of ARCv2/ARCompact support
  ARCv2: [vdk] dts files and defconfig for HS38 VDK
  ARCv2: [axs103] Support ARC SDP FPGA platform for HS38x cores
  ARC: [axs101] Prepare for AXS103
  ARCv2: [nsim*hs*] Support simulation platforms for HS38x cores
  ARCv2: All bits in place, allow ARCv2 builds
  ARCv2: SLC: Handle explcit flush for DMA ops (w/o IO-coherency)
  ARCv2: STAR 9000837815 workaround hardware exclusive transactions livelock
  ARC: Reduce bitops lines of code using macros
  ARCv2: barriers
  arch: conditionally define smp_{mb,rmb,wmb}
  ARC: add smp barriers around atomics per Documentation/atomic_ops.txt
  ARC: add compiler barrier to LLSC based cmpxchg
  ARCv2: SMP: intc: IDU 2nd level intc for dynamic IRQ distribution
  ARCv2: SMP: clocksource: Enable Global Real Time counter
  ARCv2: SMP: ARConnect debug/robustness
  ARCv2: SMP: Support ARConnect (MCIP) for Inter-Core-Interrupts et al
  ARC: make plat_smp_ops weak to allow over-rides
  ARCv2: clocksource: Introduce 64bit local RTC counter
  ...
2015-07-01 09:24:26 -07:00
Akinobu Mita 92ed932d30 arc: use for_each_sg()
This replaces the plain loop over the sglist array with for_each_sg()
macro which consists of sg_next() function calls.  Since arc doesn't
select ARCH_HAS_SG_CHAIN, it is not necessary to use for_each_sg() in
order to loop over each sg element.  But this can help find problems with
drivers that do not properly initialize their sg tables when
CONFIG_DEBUG_SG is enabled.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-30 19:44:58 -07:00
Vineet Gupta 40b8ad8f76 ARC: Fix build failures for ARCompact in linux-next after ARCv2 support
Reported-by: Guenter Roeck <private@roeck-us.net>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-28 20:30:13 +05:30
Vineet Gupta d1c6c2fbcd ARCv2: Allow older gcc to cope with new regime of ARCv2/ARCompact support
-no-ll64 is specific to ARCv2 ISA, and is obviously not supported by
older ARC gcc - in this case the one hosted by linux-next sanity build
service.

Ensure that it doesn't get included for ISA_ARCOMPACT

Reported-by: Guenter Roeck <private@roeck-us.net>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-28 19:47:22 +05:30
Linus Torvalds ad90fb9751 Merge branch 'for-4.2/sg' of git://git.kernel.dk/linux-block
Pull asm/scatterlist.h removal from Jens Axboe:
 "We don't have any specific arch scatterlist anymore, since parisc
  finally switched over.  Kill the include"

* 'for-4.2/sg' of git://git.kernel.dk/linux-block:
  remove scatterlist.h generation from arch Kbuild files
  remove <asm/scatterlist.h>
2015-06-25 15:22:36 -07:00
Laurent Dufour 2ae416b142 mm: new mm hook framework
CRIU is recreating the process memory layout by remapping the checkpointee
memory area on top of the current process (criu).  This includes remapping
the vDSO to the place it has at checkpoint time.

However some architectures like powerpc are keeping a reference to the
vDSO base address to build the signal return stack frame by calling the
vDSO sigreturn service.  So once the vDSO has been moved, this reference
is no more valid and the signal frame built later are not usable.

This patch serie is introducing a new mm hook framework, and a new
arch_remap hook which is called when mremap is done and the mm lock still
hold.  The next patch is adding the vDSO remap and unmap tracking to the
powerpc architecture.

This patch (of 3):

This patch introduces a new set of header file to manage mm hooks:
- per architecture empty header file (arch/x/include/asm/mm-arch-hooks.h)
- a generic header (include/linux/mm-arch-hooks.h)

The architecture which need to overwrite a hook as to redefine it in its
header file, while architecture which doesn't need have nothing to do.

The default hooks are defined in the generic header and are used in the
case the architecture is not defining it.

In a next step, mm hooks defined in include/asm-generic/mm_hooks.h should
be moved here.

Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-24 17:49:41 -07:00
Ruud Derwig 2924cd18c4 ARCv2: [vdk] dts files and defconfig for HS38 VDK
- CONFIG_ARC_UBOOT_SUPPORT to handle arguments passed in r0, r1, r2
 - CONFIG_DEVTMPFS_MOUNT for mouting rootfs since it uses external cpio
   for rootfs

Cc: Grant Likely <grant.likely@linaro.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: devicetree@vger.kernel.org
Signed-off-by: Ruud Derwig <rderwig@synopsys.com>
[vgupta: folded the Main baord DT files for smp/up into one]
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-25 06:00:21 +05:30
Vineet Gupta 5fa2daaa8d ARCv2: [axs103] Support ARC SDP FPGA platform for HS38x cores
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: devicetree@vger.kernel.org
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-25 06:00:20 +05:30
Alexey Brodkin e0183f5230 ARC: [axs101] Prepare for AXS103
To avoid duplicating the MB DTS file, move the MB intc entry into cpu
card specific file

Cc: Grant Likely <grant.likely@linaro.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: devicetree@vger.kernel.org
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-25 06:00:20 +05:30
Vineet Gupta a12ebe16a5 ARCv2: [nsim*hs*] Support simulation platforms for HS38x cores
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: devicetree@vger.kernel.org
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-25 06:00:19 +05:30
Vineet Gupta 65bfbcdfde ARCv2: All bits in place, allow ARCv2 builds
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-25 06:00:19 +05:30
Vineet Gupta 795f455856 ARCv2: SLC: Handle explcit flush for DMA ops (w/o IO-coherency)
L2 cache on ARCHS processors is called SLC (System Level Cache)
For working DMA (in absence of hardware assisted IO Coherency) we need
to manage SLC explicitly when buffers transition between cpu and
controllers.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-25 06:00:19 +05:30
Vineet Gupta a5c8b52abe ARCv2: STAR 9000837815 workaround hardware exclusive transactions livelock
A quad core SMP build could get into hardware livelock with concurrent
LLOCK/SCOND. Workaround that by adding a PREFETCHW which is serialized by
SCU (System Coherency Unit). It brings the cache line in Exclusive state
and makes others invalidate their lines. This gives enough time for
winner to complete the LLOCK/SCOND, before others can get the line back.

The prefetchw in the ll/sc loop is not nice but this is the only
software workaround for current version of RTL.

Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-25 06:00:18 +05:30
Vineet Gupta 04e2eee4b0 ARC: Reduce bitops lines of code using macros
No semantical changes !

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-25 06:00:18 +05:30
Vineet Gupta b8a0330239 ARCv2: barriers
ARCv2 based HS38 cores are weakly ordered and thus explicit barriers for
kernel proper.

SMP barrier is provided by DMB instruction which also guarantees local
barrier hence used as backend of smp_*mb() as well as *mb() APIs

Also hookup barriers into MMIO accessors to avoid ordering issues in IO

Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-25 06:00:17 +05:30
Vineet Gupta 2576c28e3f ARC: add smp barriers around atomics per Documentation/atomic_ops.txt
- arch_spin_lock/unlock were lacking the ACQUIRE/RELEASE barriers
   Since ARCv2 only provides load/load, store/store and all/all, we need
   the full barrier

 - LLOCK/SCOND based atomics, bitops, cmpxchg, which return modified
   values were lacking the explicit smp barriers.

 - Non LLOCK/SCOND varaints don't need the explicit barriers since that
   is implicity provided by the spin locks used to implement the
   critical section (the spin lock barriers in turn are also fixed in
   this commit as explained above

Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-25 06:00:16 +05:30
Vineet Gupta d57f727264 ARC: add compiler barrier to LLSC based cmpxchg
When auditing cmpxchg call sites, Chuck noted that gcc was optimizing
away some of the desired LDs.

|	do {
|		new = old = *ipi_data_ptr;
|		new |= 1U << msg;
|	} while (cmpxchg(ipi_data_ptr, old, new) != old);

was generating to below

| 8015cef8:	ld         r2,[r4,0]  <-- First LD
| 8015cefc:	bset       r1,r2,r1
|
| 8015cf00:	llock      r3,[r4]  <-- atomic op
| 8015cf04:	brne       r3,r2,8015cf10
| 8015cf08:	scond      r1,[r4]
| 8015cf0c:	bnz        8015cf00
|
| 8015cf10:	brne       r3,r2,8015cf00  <-- Branch doesn't go to orig LD

Although this was fixed by adding a ACCESS_ONCE in this call site, it
seems safer (for now at least) to add compiler barrier to LLSC based
cmpxchg

Reported-by: Chuck Jordan <cjordan@synopsys,com>
Cc: <stable@vger.kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-25 05:59:23 +05:30
Miklos Szeredi 9bf39ab2ad vfs: add file_path() helper
Turn
	d_path(&file->f_path, ...);
into
	file_path(file, ...);

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-06-23 18:00:05 -04:00
Linus Torvalds d70b3ef54c Merge branch 'x86-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 core updates from Ingo Molnar:
 "There were so many changes in the x86/asm, x86/apic and x86/mm topics
  in this cycle that the topical separation of -tip broke down somewhat -
  so the result is a more traditional architecture pull request,
  collected into the 'x86/core' topic.

  The topics were still maintained separately as far as possible, so
  bisectability and conceptual separation should still be pretty good -
  but there were a handful of merge points to avoid excessive
  dependencies (and conflicts) that would have been poorly tested in the
  end.

  The next cycle will hopefully be much more quiet (or at least will
  have fewer dependencies).

  The main changes in this cycle were:

   * x86/apic changes, with related IRQ core changes: (Jiang Liu, Thomas
     Gleixner)

     - This is the second and most intrusive part of changes to the x86
       interrupt handling - full conversion to hierarchical interrupt
       domains:

          [IOAPIC domain]   -----
                                 |
          [MSI domain]      --------[Remapping domain] ----- [ Vector domain ]
                                 |   (optional)          |
          [HPET MSI domain] -----                        |
                                                         |
          [DMAR domain]     -----------------------------
                                                         |
          [Legacy domain]   -----------------------------

       This now reflects the actual hardware and allowed us to distangle
       the domain specific code from the underlying parent domain, which
       can be optional in the case of interrupt remapping.  It's a clear
       separation of functionality and removes quite some duct tape
       constructs which plugged the remap code between ioapic/msi/hpet
       and the vector management.

     - Intel IOMMU IRQ remapping enhancements, to allow direct interrupt
       injection into guests (Feng Wu)

   * x86/asm changes:

     - Tons of cleanups and small speedups, micro-optimizations.  This
       is in preparation to move a good chunk of the low level entry
       code from assembly to C code (Denys Vlasenko, Andy Lutomirski,
       Brian Gerst)

     - Moved all system entry related code to a new home under
       arch/x86/entry/ (Ingo Molnar)

     - Removal of the fragile and ugly CFI dwarf debuginfo annotations.
       Conversion to C will reintroduce many of them - but meanwhile
       they are only getting in the way, and the upstream kernel does
       not rely on them (Ingo Molnar)

     - NOP handling refinements. (Borislav Petkov)

   * x86/mm changes:

     - Big PAT and MTRR rework: making the code more robust and
       preparing to phase out exposing direct MTRR interfaces to drivers -
       in favor of using PAT driven interfaces (Toshi Kani, Luis R
       Rodriguez, Borislav Petkov)

     - New ioremap_wt()/set_memory_wt() interfaces to support
       Write-Through cached memory mappings.  This is especially
       important for good performance on NVDIMM hardware (Toshi Kani)

   * x86/ras changes:

     - Add support for deferred errors on AMD (Aravind Gopalakrishnan)

       This is an important RAS feature which adds hardware support for
       poisoned data.  That means roughly that the hardware marks data
       which it has detected as corrupted but wasn't able to correct, as
       poisoned data and raises an APIC interrupt to signal that in the
       form of a deferred error.  It is the OS's responsibility then to
       take proper recovery action and thus prolonge system lifetime as
       far as possible.

     - Add support for Intel "Local MCE"s: upcoming CPUs will support
       CPU-local MCE interrupts, as opposed to the traditional system-
       wide broadcasted MCE interrupts (Ashok Raj)

     - Misc cleanups (Borislav Petkov)

   * x86/platform changes:

     - Intel Atom SoC updates

  ... and lots of other cleanups, fixlets and other changes - see the
  shortlog and the Git log for details"

* 'x86-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (222 commits)
  x86/hpet: Use proper hpet device number for MSI allocation
  x86/hpet: Check for irq==0 when allocating hpet MSI interrupts
  x86/mm/pat, drivers/infiniband/ipath: Use arch_phys_wc_add() and require PAT disabled
  x86/mm/pat, drivers/media/ivtv: Use arch_phys_wc_add() and require PAT disabled
  x86/platform/intel/baytrail: Add comments about why we disabled HPET on Baytrail
  genirq: Prevent crash in irq_move_irq()
  genirq: Enhance irq_data_to_desc() to support hierarchy irqdomain
  iommu, x86: Properly handle posted interrupts for IOMMU hotplug
  iommu, x86: Provide irq_remapping_cap() interface
  iommu, x86: Setup Posted-Interrupts capability for Intel iommu
  iommu, x86: Add cap_pi_support() to detect VT-d PI capability
  iommu, x86: Avoid migrating VT-d posted interrupts
  iommu, x86: Save the mode (posted or remapped) of an IRTE
  iommu, x86: Implement irq_set_vcpu_affinity for intel_ir_chip
  iommu: dmar: Provide helper to copy shared irte fields
  iommu: dmar: Extend struct irte for VT-d Posted-Interrupts
  iommu: Add new member capability to struct irq_remap_ops
  x86/asm/entry/64: Disentangle error_entry/exit gsbase/ebx/usermode code
  x86/asm/entry/32: Shorten __audit_syscall_entry() args preparation
  x86/asm/entry/32: Explain reloading of registers after __audit_syscall_entry()
  ...
2015-06-22 17:59:09 -07:00
Vineet Gupta eaf0ecc33f ARCv2: SMP: intc: IDU 2nd level intc for dynamic IRQ distribution
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-22 14:06:57 +05:30
Vineet Gupta 72d7288061 ARCv2: SMP: clocksource: Enable Global Real Time counter
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-22 14:06:57 +05:30
Vineet Gupta aa6083ed50 ARCv2: SMP: ARConnect debug/robustness
- Handle possible interrupt coalescing from MCIP
- chk if prev IPI ack before sending new

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-22 14:06:57 +05:30
Vineet Gupta 82fea5a1bb ARCv2: SMP: Support ARConnect (MCIP) for Inter-Core-Interrupts et al
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-22 14:06:56 +05:30
Vineet Gupta 173eaafaed ARC: make plat_smp_ops weak to allow over-rides
This allows platforms to provide their own cpu wakeup routines
as well as IPI send / clear backends, while allowing a SMP kernel w/o
any such backend to build/boot

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-22 14:06:56 +05:30
Vineet Gupta aa93e8ef98 ARCv2: clocksource: Introduce 64bit local RTC counter
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-22 14:06:56 +05:30
Vineet Gupta 8922bc3058 ARCv2: Adhere to Zero Delay loop restriction
Branch insn can't be scheduled as last insn of Zero Overhead loop

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-22 14:06:56 +05:30
Claudiu Zissulescu 1f7e3dc0ba ARCv2: optimised string/mem lib routines
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-22 14:06:56 +05:30
Vineet Gupta bcc4d65abe ARCv2: MMUv4: support aliasing icache config
This is also default for AXS103 release

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-22 14:06:56 +05:30
Vineet Gupta d1f317d825 ARCv2: MMUv4: cache programming model changes
Caveats about cache flush on ARCv2 based cores

- dcache is PIPT so paddr is sufficient for cache maintenance ops (no
  need to setup PTAG reg

- icache is still VIPT but only aliasing configs need PTAG setup

So basically this is departure from MMU-v3 which always need vaddr in
line ops registers (DC_IVDL, DC_FLDL, IC_IVIL) but paddr in DC_PTAG,
IC_PTAG respectively.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-22 14:06:55 +05:30
Vineet Gupta d7a512bfe0 ARCv2: MMUv4: TLB programming Model changes
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-22 14:06:55 +05:30
Vineet Gupta 4de0e52867 ARCv2: STAR 9000814690: Really Re-enable interrupts to avoid deadlocks
The issue was, on HS when interrupt is taken, IRQ_ACT is set and that is
NOT cleared unless we do RTIE (or manually clear it). Linux interrupt
handling has top and bottom halves. Latter lead to softirqs (which can
reschedule) AND expect interrupts to be REALLY re-enabled which was NOT
happening for us since we only SETI, dont clear IRQ_ACT

So we can have a state when both cores have taken interrupt (IRQ_ACT set),
get rescheduled, both send IPI and wait in CSD lock which will never be
cleared as cores can't take the pending IPI IRQ due to existing IRQ_ACT
set.

So local_irq_enable() now drops the IRQ_ACT.act bit to re-enable IRQs.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-22 14:06:55 +05:30
Vineet Gupta 0d7b8855a0 ARCv2: STAR 9000808988: signals involving Delay Slot
Reported by Anton as LTP:munmap01 failing with Illegal Instruction
Exception.

   --------------------->8--------------------------------------
   mmap2(NULL, 24576, PROT_READ|PROT_WRITE, MAP_SHARED, 3, 0) = 0x200d2000
   munmap(0x200d2000, 24576)               = 0
   --- SIGSEGV {si_signo=SIGSEGV, si_code=SEGV_MAPERR, si_addr=0x200d2000}
   ---
   potentially unexpected fatal signal 4.
   Path: /munmap01
   CPU: 0 PID: 61 Comm: munmap01 Not tainted 3.13.0-g5d5c46d9a556 #8
   task: 9f1a8000 ti: 9f154000 task.ti: 9f154000

   [ECR   ]: 0x00020100 => Illegal Insn
   [EFA   ]: 0x0001354c
   [BLINK ]: 0x200515d4
   [ERET  ]: 0x1354c
       @off 0x1354c in [/munmap01]
       VMA: 0x00010000 to 0x00018000
   [STAT32]: 0x800802c0
   ...
   --------------------->8--------------------------------------

The issue was
1. munmap01 accessed unmapped memory (on purpose) with signal handler
   installed for SIGSEGV

2. The faulting instruction happened to be in Delay Slot
   00011864 <main>:
      11908:	bl.d       13284 <tst_resm>
      1190c:	stb        r16,[r2]

3. kernel sets up the reg file for signal handler and correctly clears
   the DE bit in pt_regs->status32 placeholder

4. However RESTORE_CALLEE_SAVED_USER macro is not adjusted for ARCv2,
   and it over-writes the above with orig/stale value of status32

5. After RTIE, userspace signal handler executes a non branch
   instruction with DE bit set, triggering Illegal Instruction Exception.

Reported-by: Anton Kolesov <akolesov@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-22 14:06:55 +05:30
Vineet Gupta 4255b07f2c ARCv2: STAR 9000793984: Handle return from intr to Delay Slot
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-22 14:06:55 +05:30
Vineet Gupta 1f6ccfff63 ARCv2: Support for ARCv2 ISA and HS38x cores
The notable features are:
    - SMP configurations of upto 4 cores with coherency
    - Optional L2 Cache and IO-Coherency
    - Revised Interrupt Architecture (multiple priorites, reg banks,
        auto stack switch, auto regfile save/restore)
    - MMUv4 (PIPT dcache, Huge Pages)
    - Instructions for
	* 64bit load/store: LDD, STD
	* Hardware assisted divide/remainder: DIV, REM
	* Function prologue/epilogue: ENTER_S, LEAVE_S
	* IRQ enable/disable: CLRI, SETI
	* pop count: FFS, FLS
	* SETcc, BMSKN, XBFU...

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-22 14:06:55 +05:30
Vineet Gupta 820970a5aa ARCv2: [intc] HS38 core interrupt controller
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-22 14:06:55 +05:30
Vineet Gupta 10d11e580c ARC: uncached base is hard constant for ARC, don't save it
ioremap already uses the hard define, just make sure BCR value matches
that

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-22 14:06:54 +05:30
Vineet Gupta 5793e273a1 ARC: intc: split into ARCompact ISA specific, common bits
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-19 18:09:40 +05:30
Vineet Gupta 6ffb9c8c5f ARC: Make way for pt_regs != user_regs_struct
These have been register compatible so far. However ARCv2 mandates
different pt_regs layout (due to h/w auto save). To keep pt_regs same
for both, we start by removing the assumption - used mainly for block
copies between the 2 structs in signal handling and ptrace

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-19 18:09:40 +05:30
Vineet Gupta 5a343b9fe2 ARC: entry.S: [arcompact] simplify SWITCH_TO_KERNEL_STK
Previously this macro was overloaded with stack switching, saving SP at right
slot in pt_regs, saving/setup of r25 and setting SP baseline to where
pt_regs->sp is saved (vs. bottom of pt_regs)

Now it only does SP switch, and leaves SP pointing to bottom of pt_regs.

r25 saving is no longer done here to allow for future reordering of
regfile in pt_regs w/o touching this macro

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-19 18:09:40 +05:30
Vineet Gupta c80417b612 ARC: entry.S: use single EXCEPTION_PROLOGUE
Returning from pure kernel mode and exception mode use the same code
anyways. Remove one the duplicate blocks

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-19 18:09:39 +05:30
Vineet Gupta 62fb64034d ARC: entry.S: micro-optimize Trap handler
Elide the need to re-read ECR in Trap handler by ensuring that
EXCEPTION_PROLOGUE does that at the very end just before returning
to Trap handler

ARCv2 EXCEPTION_PROLOGUE already did that, so same for ARcompact and the
common trap handler adjusted to use cached ECR

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-19 18:09:39 +05:30
Vineet Gupta c7e6d79204 ARC: entry.S: move some code around for cache locality in return path
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-19 18:09:38 +05:30
Vineet Gupta 6d1a20b1d2 ARC: entry.S: split into ARCompact ISA specific, common bits
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-19 18:09:38 +05:30
Vineet Gupta c10d6969b0 ARC: entry.S: Ensure that restore_regs is local to compilation unit
This fixes the possible link/relo errors, since restore_regs will be
provided by ISA code, but called from ARC common code.
The .L prefix reassures binutils that it will be in same compilation
unit.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-19 18:09:37 +05:30
Vineet Gupta 4bf4564b27 ARC: entry.S: comments cleanup
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-19 18:09:37 +05:30
Vineet Gupta a8717d2808 ARC: entry.S: Trap handler to use r10 for syscall vs. brkpt decision
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-19 18:09:36 +05:30
Vineet Gupta 9b8c7d1e71 ARC: entry.S: FAKE_RET_FROM_EXCPN can always use r9
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-19 18:09:36 +05:30
Vineet Gupta a615b47dbf ARC: entry.S: confine EXCEPTION_* macros to one file
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-19 18:09:35 +05:30
Vineet Gupta f033737e77 ARC: entry.S: canonical'ize EXCEPTION_{PROLOGUE,EPILOGUE}
-EXCEPTION_EPILOGUE introduced
-EXCEPTION_PROLOGUE now also includes reg file saving

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-19 18:09:35 +05:30
Vineet Gupta 09f3b37e4e ARC: entry.S: Introduce INTERRUPT_{PROLOGUE,EPILOGUE}
-common'ize macros for level 1 and level 2 interrupts

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-19 18:09:34 +05:30
Vineet Gupta fbfa26ae3b ARC: entry.S: common'ize scrtach reg freeup in intr + exceptions
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-19 18:09:34 +05:30
Vineet Gupta 11e14896ea ARC: untangle cache flush loop
- Remove the ifdef'ery and write distinct versions for each mmu ver even
  if there is some code duplication

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-19 18:09:33 +05:30
Vineet Gupta 6c31068137 ARC: cacheflush: No need to retain DC_CTRL from __before_dc_op()
That is because __after_dc_op() already reads it for status check, so it
is better anyways to use that "newer" value.

Also reduces the clutter in callers for passing from/to these routines.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-19 18:09:33 +05:30
Vineet Gupta 8ea2ddff41 ARC: cacheflush: move some code around, delete old comments
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-19 18:09:33 +05:30
Vineet Gupta 8362c389a4 ARC: mm/cache_arc700.c -> mm/cache.c
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-19 18:09:32 +05:30
Vineet Gupta db7e985526 ARC: [axs101] Add missing __init annotations
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-19 18:09:32 +05:30
Alexey Brodkin 7cacc5bf60 ARC: [axs101] STAR 9000799830: Fix SD cards support
As DW Mobile Storage databook says it's required to use "Hold Register"
if card is enumerated in SDR12 or SDR25 modes.
It means we need to act in the same way as in Altera's Socfpga
implementation - set "use hold reg" bit in commad.

Note that for upstream proper solution would be to remove
dw_mci_pltfm_prepare_command() at all and set the bit right in
dw_mci_prepare_command() for all platforms.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-19 18:09:31 +05:30
Vineet Gupta 749aa0e11a ARC: [axs101] Tweak DDR port aperture mappings for performance
Route all MB originated traffic to DDR Port 1 and keep Port 0 for CPU
traffic only

Basic system parameters
--------------------------------------------------------------------------------------
        Host                 OS Description 				Mhz  tlb   cache  mem   scal
                                                			    pages  line   par   load
                                                      				   bytes
----------------- ------------- --------------------------------------- ---- ----- ----- ------ ----
axs101-sd-2-new-f Linux 3.13.0+ axs101-sd-2-new-fw-old-img-rerun    	739  	8    32 1.1100    1
axs101-sd-3-arc-3 Linux 3.13.9+ axs101-sd-3-arc-3.13-tip-regression 	735  	8    32 1.1000    1
axs101-sd-9-diffe Linux 3.13.11 axs101-sd-9-different-tweak         	740  	8    32 1.0000    1

Processor, Processes - times in microseconds - smaller is better
------------------------------------------------------------------------------
Host                 OS  Mhz null null      open slct sig  sig  fork exec sh
                             call  I/O stat clos TCP  inst hndl proc proc proc
--------- ------------- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ----
axs101-sd Linux 3.13.0+  739 0.50 0.88 5.38 14.6 34.1 0.92 5.18 2135 6555 12.K
axs101-sd Linux 3.13.9+  735 0.50 0.90 5.89 19.2 81.4 0.94 4.08 2560 8559 15.K
axs101-sd Linux 3.13.11  740 0.50 0.88 4.45 17.8 34.4 0.94 3.25 2052 6493 12.K
                                                 ^^^^                     ^^^^

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-19 18:09:31 +05:30
Vineet Gupta 8d0d56ba24 ARC: [axs101] support early 8250 uart
Earlycon calculates UART clock as "BASE_BAUD * 16". In case of ARC
"BASE_BAUD" is calculated dynamically in runtime, basically it is an
alias to arc_early_base_baud(), which in turn just does
"arc_base_baud/16".

8250 UART on AXS/SDP board uses 33.3MHz clock source which is set in
"arc_base_baud" with this change.

Additional compatibility string "snps,arc-sdp" is introduced as well
because there're different flavours of AXS boards but they all share the
same motherboard and so it's possible to re-use the same code for
motherbord even if CPU daughterboard changes.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-19 18:09:30 +05:30
Alexey Brodkin 556cc1c5f5 ARC: [axs101] Add support for AXS101 SDP (software development platform)
The AXS10x platforms consist of a mainboard with peripherals,
on which several daughter cards can be placed. The daughter cards
typically contain a CPU and memory.

Signed-off-by: Mischa Jonker <mjonker@synopsys.com>
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-19 18:09:30 +05:30
Vineet Gupta 4db27dca60 ARC: mm: document system mem map clearly
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-19 18:09:29 +05:30
Vineet Gupta def32fad84 ARC: stack unwinder to bail if PC is not kernel mode
Currently, it doesn't invoke the callback but continues to unwind

Also while at it - simplify the code a bit

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-19 18:09:29 +05:30
Tobias Klauser 082ae1e157 ARC: perf: Remove unnecessary local variable
Directly return the result of perf_pmu_register() in
arc_pmu_device_probe() instead of assigning and returning variable ret.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-19 18:09:28 +05:30